diff --git a/.circleci/config.yml b/.circleci/config.yml
index ea1d528f34b01..255466e833027 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -24,6 +24,11 @@ machine-mac: &machine-mac
   macos:
     xcode: "8.3.3"
 
+machine-mac-large: &machine-mac-large
+  resource_class: large
+  macos:
+    xcode: "8.3.3"
+
 # Build configurations options.
 env-debug-build: &env-debug-build
   GN_CONFIG: //electron/build/args/debug.gn
@@ -34,6 +39,7 @@ env-testing-build: &env-testing-build
 env-release-build: &env-release-build
   GN_CONFIG: //electron/build/args/release.gn
   STRIP_BINARIES: true
+  GENERATE_SYMBOLS: true
 
 env-headless-testing: &env-headless-testing
   DISPLAY: ':99.0'
@@ -79,6 +85,21 @@ env-enable-sccache: &env-enable-sccache
 env-send-slack-notifications: &env-send-slack-notifications
   NOTIFY_SLACK: true
 
+env-linux-medium: &env-linux-medium
+  NUMBER_OF_NINJA_PROCESSES: 3
+
+env-linux-2xlarge: &env-linux-2xlarge
+  NUMBER_OF_NINJA_PROCESSES: 18
+
+env-machine-mac: &env-machine-mac
+  NUMBER_OF_NINJA_PROCESSES: 6
+
+env-mac-large: &env-mac-large
+  NUMBER_OF_NINJA_PROCESSES: 10
+
+env-disable-crash-reporter-tests: &env-disable-crash-reporter-tests
+  DISABLE_CRASH_REPORTER_TESTS: true
+
 # Individual (shared) steps.
 step-maybe-notify-slack-failure: &step-maybe-notify-slack-failure
   run:
@@ -157,6 +178,16 @@ step-install-nodejs-on-mac: &step-install-nodejs-on-mac
         echo 'export PATH="/usr/local/opt/node@10/bin:$PATH"' >> $BASH_ENV
       fi
 
+step-install-gnutar-on-mac: &step-install-gnutar-on-mac
+  run:
+    name: Install gnu-tar on macos
+    command: |
+      if [ "`uname`" == "Darwin" ]; then
+        brew update
+        brew install gnu-tar
+        ln -fs /usr/local/bin/gtar /usr/local/bin/tar
+      fi
+
 step-gn-gen-default: &step-gn-gen-default
   run:
     name: Default GN gen
@@ -169,13 +200,13 @@ step-electron-build: &step-electron-build
     name: Electron build
     command: |
       cd src
-      ninja -C out/Default electron -j18
+      ninja -C out/Default electron -j $NUMBER_OF_NINJA_PROCESSES
 
 step-maybe-electron-dist-strip: &step-maybe-electron-dist-strip
   run:
     name: Strip electron binaries
     command: |
-      if [ "$STRIP_BINARIES" == "true" ]; then
+      if [ "$STRIP_BINARIES" == "true" ] && [ "`uname`" != "Darwin" ]; then
         cd src
         electron/script/strip-binaries.py --target-cpu="$TARGET_ARCH"
       fi
@@ -197,9 +228,7 @@ step-electron-chromedriver-build: &step-electron-chromedriver-build
     name: Build chromedriver.zip
     command: |
       cd src
-      # NOTE(alexeykuzmin): -j3 because chromedriver is currently built
-      # on a smaller size machine and ninja mis-detects the number of CPUs available.
-      ninja -C out/Default chrome/test/chromedriver -j3
+      ninja -C out/Default chrome/test/chromedriver -j $NUMBER_OF_NINJA_PROCESSES
       electron/script/strip-binaries.py --target-cpu="$TARGET_ARCH" --file $PWD/out/Default/chromedriver
       ninja -C out/Default electron:electron_chromedriver_zip
 
@@ -237,14 +266,11 @@ step-persist-data-for-tests: &step-persist-data-for-tests
   persist_to_workspace:
     root: .
     paths:
-      # To run `gn args` for that dir from the "verify-ffmpeg" script.
-      - src/out/Default/args.gn
-      - src/out/Default/build.ninja
-
       # Build artifacts
       - src/out/Default/dist.zip
       - src/out/Default/mksnapshot.zip
       - src/out/Default/gen/node_headers
+      - src/out/ffmpeg/ffmpeg.zip
 
 step-electron-dist-unzip: &step-electron-dist-unzip
   run:
@@ -255,6 +281,13 @@ step-electron-dist-unzip: &step-electron-dist-unzip
       # TODO(alexeykuzmin): Remove '-o' when it's no longer needed.
       unzip -o dist.zip
 
+step-ffmpeg-unzip: &step-ffmpeg-unzip
+  run:
+    name: Unzip ffmpeg.zip
+    command: |
+      cd src/out/ffmpeg
+      unzip -o ffmpeg.zip
+
 step-mksnapshot-unzip: &step-mksnapshot-unzip
   run:
     name: Unzip mksnapshot.zip
@@ -274,9 +307,7 @@ step-ffmpeg-build: &step-ffmpeg-build
     name: Non proprietary ffmpeg build
     command: |
       cd src
-      # NOTE(jeremy): -j3 because ffmpeg is currently built on a smaller
-      # machine size and ninja mis-detects the number of CPUs available.
-      ninja -C out/ffmpeg electron:electron_ffmpeg_zip -j3
+      ninja -C out/ffmpeg electron:electron_ffmpeg_zip -j $NUMBER_OF_NINJA_PROCESSES
 
 step-verify-ffmpeg: &step-verify-ffmpeg
   run:
@@ -327,33 +358,35 @@ step-mksnapshot-build: &step-mksnapshot-build
           electron/script/strip-binaries.py --file $PWD/out/Default/mksnapshot
         fi
       fi
-      # NOTE(jeremy): -j3 because mksnapshot is currently built on a smaller
-      # machine size and ninja mis-detects the number of CPUs available.
-      ninja -C out/Default electron:electron_mksnapshot_zip -j3
+      ninja -C out/Default electron:electron_mksnapshot_zip -j $NUMBER_OF_NINJA_PROCESSES
 
 step-mksnapshot-store: &step-mksnapshot-store
   store_artifacts:
     path: src/out/Default/mksnapshot.zip
     destination: mksnapshot.zip
 
-step-build-dump-syms: &step-build-dump-syms
+step-maybe-build-dump-syms: &step-maybe-build-dump-syms
   run:
     name: Build dump_syms binary
     command: |
-      cd src
-      # Build needed dump_syms executable
-      ninja -C out/Default third_party/breakpad:dump_syms
+      if [ "$GENERATE_SYMBOLS" == "true" ]; then
+        cd src
+        # Build needed dump_syms executable
+        ninja -C out/Default third_party/breakpad:dump_syms
+      fi
 
-step-generate-breakpad-symbols: &step-generate-breakpad-symbols
+step-maybe-generate-breakpad-symbols: &step-maybe-generate-breakpad-symbols
   run:
     name: Generate breakpad symbols
     command: |
-      cd src
-      export BUILD_PATH="$PWD/out/Default"
-      export DEST_PATH="$BUILD_PATH/breakpad_symbols"
-      electron/script/dump-symbols.py -b $BUILD_PATH -d $DEST_PATH -v
+      if [ "$GENERATE_SYMBOLS" == "true" ]; then
+        cd src
+        export BUILD_PATH="$PWD/out/Default"
+        export DEST_PATH="$BUILD_PATH/breakpad_symbols"
+        electron/script/dump-symbols.py -b $BUILD_PATH -d $DEST_PATH -v
+      fi
 
-step-zip-symbols: &step-zip-symbols
+step-maybe-zip-symbols: &step-maybe-zip-symbols
   run:
     name: Zip symbols
     command: |
@@ -378,9 +411,7 @@ step-maybe-native-mksnapshot-build: &step-maybe-native-mksnapshot-build
     command: |
       if [ "$BUILD_NATIVE_MKSNAPSHOT" == "1" ]; then
         cd src
-        # NOTE(jeremy): -j3 because mksnapshot is currently built on a smaller
-        # machine size and ninja mis-detects the number of CPUs available.
-        ninja -C out/native_mksnapshot electron:electron_mksnapshot_zip -j3
+        ninja -C out/native_mksnapshot electron:electron_mksnapshot_zip -j $NUMBER_OF_NINJA_PROCESSES
       else
         echo 'Skipping native mksnapshot build for non arm build'
       fi
@@ -412,12 +443,24 @@ step-maybe-trigger-arm-test: &step-maybe-trigger-arm-test
         echo "Triggering electron-$TARGET_ARCH-testing build on VSTS"
         node electron/script/ci-release-build.js --job=electron-$TARGET_ARCH-testing --ci=VSTS --armTest --circleBuildNum=$CIRCLE_BUILD_NUM $CIRCLE_BRANCH
       fi
+
+step-maybe-generate-typescript-defs: &step-maybe-generate-typescript-defs
+  run:
+    name: Generate type declarations
+    command: |
+      if [ "`uname`" == "Darwin" ]; then
+        cd src/electron
+        npm run create-typescript-definitions
+      fi
+
 # Lists of steps.
 steps-checkout: &steps-checkout
   steps:
     - *step-checkout-electron
     - *step-depot-tools-get
     - *step-depot-tools-add-to-path
+    - *step-install-nodejs-on-mac
+    - *step-install-gnutar-on-mac
 
     - restore_cache:
         paths:
@@ -474,6 +517,7 @@ steps-electron-build-for-tests: &steps-electron-build-for-tests
         at: .
     - *step-depot-tools-add-to-path
     - *step-setup-env-for-build
+    - *step-install-nodejs-on-mac
     - *step-gn-gen-default
 
     # Electron app
@@ -506,11 +550,9 @@ steps-electron-build-for-tests: &steps-electron-build-for-tests
     # Save all data needed for a further tests run.
     - *step-persist-data-for-tests
 
-    # Breakpad symbols.
-    # TODO(alexeykuzmin): We should do it only in nightly builds.
-    - *step-build-dump-syms
-    - *step-generate-breakpad-symbols
-    - *step-zip-symbols
+    - *step-maybe-build-dump-syms
+    - *step-maybe-generate-breakpad-symbols
+    - *step-maybe-zip-symbols
 
     # Trigger tests on arm hardware if needed
     - *step-maybe-trigger-arm-test
@@ -522,6 +564,7 @@ steps-electron-build-for-publish: &steps-electron-build-for-publish
     - *step-checkout-electron
     - *step-depot-tools-get
     - *step-depot-tools-add-to-path
+    - *step-install-nodejs-on-mac
     - *step-gclient-sync
     - *step-setup-env-for-build
     - *step-gn-gen-default
@@ -531,9 +574,9 @@ steps-electron-build-for-publish: &steps-electron-build-for-publish
     - *step-maybe-electron-dist-strip
     - *step-electron-dist-build
     - *step-electron-dist-store
-    - *step-build-dump-syms
-    - *step-generate-breakpad-symbols
-    - *step-zip-symbols
+    - *step-maybe-build-dump-syms
+    - *step-maybe-generate-breakpad-symbols
+    - *step-maybe-zip-symbols
 
     # mksnapshot
     - *step-mksnapshot-build
@@ -558,6 +601,9 @@ steps-electron-build-for-publish: &steps-electron-build-for-publish
     - *step-ffmpeg-build
     - *step-ffmpeg-store
 
+    # typescript defs
+    - *step-maybe-generate-typescript-defs
+
     # Publish
     - *step-electron-publish
 
@@ -586,26 +632,6 @@ steps-native-mksnapshot-build: &steps-native-mksnapshot-build
 
     - *step-maybe-notify-slack-failure
 
-steps-ffmpeg-build: &steps-ffmpeg-build
-  steps:
-    - attach_workspace:
-        at: .
-    - *step-depot-tools-add-to-path
-    - *step-setup-env-for-build
-
-    - *step-ffmpeg-gn-gen
-    - *step-ffmpeg-build
-    - *step-ffmpeg-store
-
-    - persist_to_workspace:
-        root: .
-        paths:
-          - src/out/ffmpeg/libffmpeg.so
-          - src/out/ffmpeg/ffmpeg.zip
-
-    - *step-show-sccache-stats
-    - *step-maybe-notify-slack-failure
-
 steps-native-tests: &steps-native-tests
   steps:
     - attach_workspace:
@@ -643,6 +669,7 @@ steps-verify-ffmpeg: &steps-verify-ffmpeg
         at: .
     - *step-depot-tools-add-to-path
     - *step-electron-dist-unzip
+    - *step-ffmpeg-unzip
     - *step-setup-linux-for-headless-testing
 
     - *step-verify-ffmpeg
@@ -680,7 +707,7 @@ steps-tests: &steps-tests
         command: |
           cd src
           export ELECTRON_OUT_DIR=Default
-          (cd electron && npm run test -- --ci)
+          (cd electron && npm run test -- --ci --enable-logging)
     - run:
         name: Check test results existence
         command: |
@@ -696,64 +723,6 @@ steps-tests: &steps-tests
 
     - *step-maybe-notify-slack-failure
 
-# Mac build are different in a few ways:
-# 1. We can't use save_cache/restore_cache on Mac,
-#   unpacking with `tar` fails with "Attempt to write to an empty file" error.
-# 2. We don't use a shared checkout job because persist_to_workspace
-#   and attach_workspace take too much time, more than the checkout itself.
-steps-build-mac: &steps-build-mac
-  steps:
-    - *step-checkout-electron
-    - *step-depot-tools-get
-    - *step-depot-tools-add-to-path
-    - *step-install-nodejs-on-mac
-    - *step-gclient-sync
-    - *step-setup-env-for-build
-    - *step-gn-gen-default
-
-    # Electron app
-    - *step-electron-build
-    - *step-electron-dist-build
-    - *step-electron-dist-store
-
-    # mksnapshot
-    - *step-mksnapshot-build
-    - *step-mksnapshot-store
-
-    # chromedriver
-    - *step-electron-chromedriver-build
-    - *step-electron-chromedriver-store
-
-    # ffmpeg
-    - *step-ffmpeg-gn-gen
-    - *step-ffmpeg-build
-    - *step-ffmpeg-store
-
-    # It would be better to verify ffmpeg as a part of a test job,
-    # but it requires `gn` to run, and it's complicated
-    # to store all gn's dependencies and configs.
-    - *step-verify-ffmpeg
-
-    - *step-verify-mksnapshot
-
-    # Node.js headers for tests
-    - *step-nodejs-headers-build
-
-    - *step-show-sccache-stats
-
-    - persist_to_workspace:
-        root: .
-        paths:
-          - src/electron
-
-    # Save all data needed for a further tests run.
-    - *step-persist-data-for-tests
-
-filter-only-prs-from-forks: &filter-only-prs-from-forks
-  filters:
-    branches:
-      only: /^pull\/.*$/
-
 chromium-upgrade-branches: &chromium-upgrade-branches
   /chromium\-upgrade\/[0-9]+/
 
@@ -764,19 +733,35 @@ jobs:
   linux-checkout:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       GCLIENT_EXTRA_ARGS: '--custom-var=checkout_arm=True --custom-var=checkout_arm64=True'
     <<: *steps-checkout
 
   linux-checkout-for-native-tests:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       GCLIENT_EXTRA_ARGS: '--custom-var=checkout_pyyaml=True'
     <<: *steps-checkout
 
+  linux-checkout-for-native-tests-with-no-patches:
+    <<: *machine-linux-2xlarge
+    environment:
+      <<: *env-linux-2xlarge
+      GCLIENT_EXTRA_ARGS: '--custom-var=apply_patches=False --custom-var=checkout_pyyaml=True'
+    <<: *steps-checkout
+
+  mac-checkout:
+    <<: *machine-mac-large
+    environment:
+      <<: *env-mac-large
+    <<: *steps-checkout
+
   # Layer 2: Builds.
   linux-x64-debug:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-debug-build
       <<: *env-enable-sccache
     <<: *steps-electron-build
@@ -784,20 +769,15 @@ jobs:
   linux-x64-testing:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-testing-build
       <<: *env-enable-sccache
     <<: *steps-electron-build-for-tests
 
-  linux-x64-ffmpeg:
-    <<: *machine-linux-medium
-    environment:
-      <<: *env-enable-sccache
-      <<: *env-send-slack-notifications
-    <<: *steps-ffmpeg-build
-
   linux-x64-chromedriver:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-release-build
       <<: *env-enable-sccache
       <<: *env-send-slack-notifications
@@ -806,6 +786,7 @@ jobs:
   linux-x64-release:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-release-build
       <<: *env-enable-sccache
       <<: *env-send-slack-notifications
@@ -814,6 +795,7 @@ jobs:
   linux-x64-publish:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       GCLIENT_EXTRA_ARGS: '--custom-var=checkout_boto=True --custom-var=checkout_requests=True'
       <<: *env-release-build
     <<: *steps-electron-build-for-publish
@@ -821,6 +803,7 @@ jobs:
   linux-ia32-debug:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-ia32
       <<: *env-debug-build
       <<: *env-enable-sccache
@@ -829,22 +812,16 @@ jobs:
   linux-ia32-testing:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-ia32
       <<: *env-testing-build
       <<: *env-enable-sccache
     <<: *steps-electron-build-for-tests
 
-  linux-ia32-ffmpeg:
-    <<: *machine-linux-medium
-    environment:
-      <<: *env-ia32
-      <<: *env-enable-sccache
-      <<: *env-send-slack-notifications
-    <<: *steps-ffmpeg-build
-
   linux-ia32-chromedriver:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-ia32
       <<: *env-release-build
       <<: *env-enable-sccache
@@ -854,6 +831,7 @@ jobs:
   linux-ia32-release:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-ia32
       <<: *env-release-build
       <<: *env-enable-sccache
@@ -863,6 +841,7 @@ jobs:
   linux-ia32-publish:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       GCLIENT_EXTRA_ARGS: '--custom-var=checkout_boto=True --custom-var=checkout_requests=True'
       <<: *env-ia32
       <<: *env-release-build
@@ -871,6 +850,7 @@ jobs:
   linux-arm-debug:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-arm
       <<: *env-debug-build
       <<: *env-enable-sccache
@@ -879,23 +859,17 @@ jobs:
   linux-arm-testing:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-arm
       <<: *env-testing-build
       <<: *env-enable-sccache
       TRIGGER_ARM_TEST: true
     <<: *steps-electron-build-for-tests
 
-  linux-arm-ffmpeg:
-    <<: *machine-linux-medium
-    environment:
-      <<: *env-arm
-      <<: *env-enable-sccache
-      <<: *env-send-slack-notifications
-    <<: *steps-ffmpeg-build
-
   linux-arm-chromedriver:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-arm
       <<: *env-release-build
       <<: *env-enable-sccache
@@ -905,6 +879,7 @@ jobs:
   linux-arm-release:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-arm
       <<: *env-release-build
       <<: *env-enable-sccache
@@ -914,6 +889,7 @@ jobs:
   linux-arm-publish:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-arm
       <<: *env-release-build
       GCLIENT_EXTRA_ARGS: '--custom-var=checkout_arm=True --custom-var=checkout_boto=True --custom-var=checkout_requests=True'
@@ -922,6 +898,7 @@ jobs:
   linux-arm-native-mksnapshot:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-arm
       <<: *env-release-build
       <<: *env-enable-sccache
@@ -931,6 +908,7 @@ jobs:
   linux-arm64-debug:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-arm64
       <<: *env-debug-build
       <<: *env-enable-sccache
@@ -939,23 +917,17 @@ jobs:
   linux-arm64-testing:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-arm64
       <<: *env-testing-build
       <<: *env-enable-sccache
       TRIGGER_ARM_TEST: true
     <<: *steps-electron-build-for-tests
 
-  linux-arm64-ffmpeg:
-    <<: *machine-linux-medium
-    environment:
-      <<: *env-arm64
-      <<: *env-enable-sccache
-      <<: *env-send-slack-notifications
-    <<: *steps-ffmpeg-build
-
   linux-arm64-chromedriver:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-arm64
       <<: *env-release-build
       <<: *env-enable-sccache
@@ -965,6 +937,7 @@ jobs:
   linux-arm64-release:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-arm64
       <<: *env-release-build
       <<: *env-enable-sccache
@@ -974,6 +947,7 @@ jobs:
   linux-arm64-publish:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-arm64
       <<: *env-release-build
       GCLIENT_EXTRA_ARGS: '--custom-var=checkout_arm64=True --custom-var=checkout_boto=True --custom-var=checkout_requests=True'
@@ -982,6 +956,7 @@ jobs:
   linux-arm64-native-mksnapshot:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-arm64
       <<: *env-release-build
       <<: *env-enable-sccache
@@ -989,33 +964,109 @@ jobs:
     <<: *steps-native-mksnapshot-build
 
   osx-testing:
-    <<: *machine-mac
+    <<: *machine-mac-large
     environment:
+      <<: *env-mac-large
       <<: *env-testing-build
       <<: *env-enable-sccache
-    <<: *steps-build-mac
+    <<: *steps-electron-build-for-tests
 
-  mas-testing:
+  osx-chromedriver:
     <<: *machine-mac
     environment:
+      <<: *env-machine-mac
+      <<: *env-release-build
+      <<: *env-enable-sccache
+      <<: *env-send-slack-notifications
+    <<: *steps-chromedriver-build
+
+  osx-release:
+    <<: *machine-mac-large
+    environment:
+      <<: *env-mac-large
+      <<: *env-release-build
+      <<: *env-enable-sccache
+    <<: *steps-electron-build-for-tests
+
+  osx-publish:
+    <<: *machine-mac-large
+    environment:
+      <<: *env-mac-large
+      <<: *env-release-build
+      GCLIENT_EXTRA_ARGS: '--custom-var=checkout_boto=True --custom-var=checkout_requests=True'
+    <<: *steps-electron-build-for-publish
+
+  mas-testing:
+    <<: *machine-mac-large
+    environment:
+      <<: *env-mac-large
       <<: *env-mas
       <<: *env-testing-build
       <<: *env-enable-sccache
-    <<: *steps-build-mac
+    <<: *steps-electron-build-for-tests
+
+  mas-chromedriver:
+    <<: *machine-mac
+    environment:
+      <<: *env-machine-mac
+      <<: *env-release-build
+      <<: *env-enable-sccache
+      <<: *env-send-slack-notifications
+    <<: *steps-chromedriver-build
+
+  mas-release:
+    <<: *machine-mac-large
+    environment:
+      <<: *env-mac-large
+      <<: *env-mas
+      <<: *env-release-build
+      <<: *env-enable-sccache
+    <<: *steps-electron-build-for-tests
+
+  mas-publish:
+    <<: *machine-mac-large
+    environment:
+      <<: *env-mac-large
+      <<: *env-mas
+      <<: *env-release-build
+      GCLIENT_EXTRA_ARGS: '--custom-var=checkout_boto=True --custom-var=checkout_requests=True'
+    <<: *steps-electron-build-for-publish
 
   # Layer 3: Tests.
   linux-x64-unittests:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-unittests
       <<: *env-testing-build
       <<: *env-enable-sccache
       <<: *env-headless-testing
     <<: *steps-native-tests
 
+  linux-x64-disabled-unittests:
+    <<: *machine-linux-2xlarge
+    environment:
+      <<: *env-linux-2xlarge
+      <<: *env-unittests
+      <<: *env-enable-sccache
+      <<: *env-headless-testing
+      TESTS_ARGS: '--only-disabled-tests'
+    <<: *steps-native-tests
+
+  linux-x64-chromium-unittests:
+    <<: *machine-linux-2xlarge
+    environment:
+      <<: *env-linux-2xlarge
+      <<: *env-unittests
+      <<: *env-enable-sccache
+      <<: *env-headless-testing
+      TESTS_ARGS: '--include-disabled-tests'
+    <<: *steps-native-tests
+
   linux-x64-browsertests:
     <<: *machine-linux-2xlarge
     environment:
+      <<: *env-linux-2xlarge
       <<: *env-browsertests
       <<: *env-testing-build
       <<: *env-enable-sccache
@@ -1025,6 +1076,7 @@ jobs:
   linux-x64-testing-tests:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-headless-testing
       <<: *env-stack-dumping
     <<: *steps-tests
@@ -1032,6 +1084,7 @@ jobs:
   linux-x64-release-tests:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-headless-testing
       <<: *env-send-slack-notifications
     <<: *steps-tests
@@ -1039,6 +1092,7 @@ jobs:
   linux-x64-verify-ffmpeg:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-headless-testing
       <<: *env-send-slack-notifications
     <<: *steps-verify-ffmpeg
@@ -1046,6 +1100,7 @@ jobs:
   linux-x64-verify-mksnapshot:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-headless-testing
       <<: *env-send-slack-notifications
     <<: *steps-verify-mksnapshot
@@ -1053,6 +1108,7 @@ jobs:
   linux-ia32-testing-tests:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-ia32
       <<: *env-headless-testing
       <<: *env-stack-dumping
@@ -1061,6 +1117,7 @@ jobs:
   linux-ia32-release-tests:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-ia32
       <<: *env-headless-testing
       <<: *env-send-slack-notifications
@@ -1069,6 +1126,7 @@ jobs:
   linux-ia32-verify-ffmpeg:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-ia32
       <<: *env-headless-testing
       <<: *env-send-slack-notifications
@@ -1077,49 +1135,118 @@ jobs:
   linux-ia32-verify-mksnapshot:
     <<: *machine-linux-medium
     environment:
+      <<: *env-linux-medium
       <<: *env-ia32
       <<: *env-headless-testing
       <<: *env-send-slack-notifications
     <<: *steps-verify-mksnapshot
 
   osx-testing-tests:
-    <<: *machine-mac
+    <<: *machine-mac-large
     environment:
+      <<: *env-mac-large
       <<: *env-stack-dumping
+      <<: *env-disable-crash-reporter-tests
     <<: *steps-tests
 
-  mas-testing-tests:
+  osx-release-tests:
+    <<: *machine-mac-large
+    environment:
+      <<: *env-mac-large
+      <<: *env-stack-dumping
+      <<: *env-send-slack-notifications
+      <<: *env-disable-crash-reporter-tests
+    <<: *steps-tests
+
+  osx-verify-ffmpeg:
+    <<: *machine-mac
+    environment:
+      <<: *env-machine-mac
+      <<: *env-send-slack-notifications
+    <<: *steps-verify-ffmpeg
+
+  osx-verify-mksnapshot:
     <<: *machine-mac
     environment:
+      <<: *env-machine-mac
+      <<: *env-send-slack-notifications
+    <<: *steps-verify-mksnapshot
+
+  mas-testing-tests:
+    <<: *machine-mac-large
+    environment:
+      <<: *env-mac-large
+      <<: *env-stack-dumping
+    <<: *steps-tests
+
+  mas-release-tests:
+    <<: *machine-mac-large
+    environment:
+      <<: *env-mac-large
       <<: *env-stack-dumping
+      <<: *env-send-slack-notifications
     <<: *steps-tests
 
+  mas-verify-ffmpeg:
+    <<: *machine-mac
+    environment:
+      <<: *env-machine-mac
+      <<: *env-send-slack-notifications
+    <<: *steps-verify-ffmpeg
+
+  mas-verify-mksnapshot:
+    <<: *machine-mac
+    environment:
+      <<: *env-machine-mac
+      <<: *env-send-slack-notifications
+    <<: *steps-verify-mksnapshot
+
   # Layer 4: Summary.
   linux-x64-release-summary:
     <<: *machine-linux-medium
     environment:
-      - *env-send-slack-notifications
+      <<: *env-linux-medium
+      <<: *env-send-slack-notifications
     steps:
       - *step-maybe-notify-slack-success
 
   linux-ia32-release-summary:
     <<: *machine-linux-medium
     environment:
-      - *env-send-slack-notifications
+      <<: *env-linux-medium
+      <<: *env-send-slack-notifications
     steps:
       - *step-maybe-notify-slack-success
 
   linux-arm-release-summary:
     <<: *machine-linux-medium
     environment:
-      - *env-send-slack-notifications
+      <<: *env-linux-medium
+      <<: *env-send-slack-notifications
     steps:
       - *step-maybe-notify-slack-success
 
   linux-arm64-release-summary:
     <<: *machine-linux-medium
     environment:
-      - *env-send-slack-notifications
+      <<: *env-linux-medium
+      <<: *env-send-slack-notifications
+    steps:
+      - *step-maybe-notify-slack-success
+
+  mas-release-summary:
+    <<: *machine-mac
+    environment:
+      <<: *env-machine-mac
+      <<: *env-send-slack-notifications
+    steps:
+      - *step-maybe-notify-slack-success
+
+  osx-release-summary:
+    <<: *machine-mac
+    environment:
+      <<: *env-machine-mac
+      <<: *env-send-slack-notifications
     steps:
       - *step-maybe-notify-slack-success
 
@@ -1163,23 +1290,26 @@ workflows:
           requires:
             - linux-checkout
 
-  build-mac-fork-prs:
+  build-mac:
     jobs:
+      - mac-checkout
       - osx-testing:
-         <<: *filter-only-prs-from-forks
+          requires:
+            - mac-checkout
+
       - osx-testing-tests:
-          <<: *filter-only-prs-from-forks
           requires:
             - osx-testing
 
       - mas-testing:
-          <<: *filter-only-prs-from-forks
+          requires:
+            - mac-checkout
+
       - mas-testing-tests:
-          <<: *filter-only-prs-from-forks
           requires:
             - mas-testing
 
-  nightly-release-test:
+  nightly-linux-release-test:
     triggers:
       - schedule:
           cron: "0 0 * * *"
@@ -1197,13 +1327,9 @@ workflows:
       - linux-x64-release-tests:
           requires:
             - linux-x64-release
-      - linux-x64-ffmpeg:
-          requires:
-            - linux-checkout
       - linux-x64-verify-ffmpeg:
           requires:
             - linux-x64-release
-            - linux-x64-ffmpeg
       - linux-x64-verify-mksnapshot:
           requires:
             - linux-x64-release
@@ -1214,7 +1340,6 @@ workflows:
           requires:
             - linux-x64-release
             - linux-x64-release-tests
-            - linux-x64-ffmpeg
             - linux-x64-verify-ffmpeg
             - linux-x64-chromedriver
 
@@ -1224,13 +1349,9 @@ workflows:
       - linux-ia32-release-tests:
           requires:
             - linux-ia32-release
-      - linux-ia32-ffmpeg:
-          requires:
-            - linux-checkout
       - linux-ia32-verify-ffmpeg:
           requires:
             - linux-ia32-release
-            - linux-ia32-ffmpeg
       - linux-ia32-verify-mksnapshot:
           requires:
             - linux-ia32-release
@@ -1241,16 +1362,12 @@ workflows:
           requires:
             - linux-ia32-release
             - linux-ia32-release-tests
-            - linux-ia32-ffmpeg
             - linux-ia32-verify-ffmpeg
             - linux-ia32-chromedriver
 
       - linux-arm-release:
           requires:
             - linux-checkout
-      - linux-arm-ffmpeg:
-           requires:
-             - linux-checkout
       - linux-arm-native-mksnapshot:
           requires:
             - linux-checkout
@@ -1260,16 +1377,12 @@ workflows:
       - linux-arm-release-summary:
           requires:
             - linux-arm-release
-            - linux-arm-ffmpeg
             - linux-arm-chromedriver
             - linux-arm-native-mksnapshot
 
       - linux-arm64-release:
           requires:
             - linux-checkout
-      - linux-arm64-ffmpeg:
-           requires:
-             - linux-checkout
       - linux-arm64-native-mksnapshot:
           requires:
             - linux-checkout
@@ -1279,10 +1392,65 @@ workflows:
       - linux-arm64-release-summary:
           requires:
             - linux-arm64-release
-            - linux-arm64-ffmpeg
             - linux-arm64-chromedriver
             - linux-arm64-native-mksnapshot
 
+  nightly-mac-release-test:
+    triggers:
+      - schedule:
+          cron: "0 0 * * *"
+          filters:
+            branches:
+              only:
+                - master
+                - *chromium-upgrade-branches
+    jobs:
+      - mac-checkout
+
+      - osx-release:
+          requires:
+            - mac-checkout
+      - osx-release-tests:
+          requires:
+            - osx-release
+      - osx-verify-ffmpeg:
+          requires:
+            - osx-release
+      - osx-verify-mksnapshot:
+          requires:
+            - osx-release
+      - osx-chromedriver:
+          requires:
+            - mac-checkout
+      - osx-release-summary:
+          requires:
+          - osx-release
+          - osx-release-tests
+          - osx-verify-ffmpeg
+          - osx-chromedriver
+
+      - mas-release:
+          requires:
+            - mac-checkout
+      - mas-release-tests:
+          requires:
+            - mas-release
+      - mas-verify-ffmpeg:
+          requires:
+            - mas-release
+      - mas-verify-mksnapshot:
+          requires:
+            - mas-release
+      - mas-chromedriver:
+          requires:
+            - mac-checkout
+      - mas-release-summary:
+          requires:
+          - mas-release
+          - mas-release-tests
+          - mas-verify-ffmpeg
+          - mas-chromedriver
+
   # Various slow and non-essential checks we run only nightly.
   # Sanitizer jobs should be added here.
   linux-checks-nightly:
diff --git a/script/ci-release-build.js b/script/ci-release-build.js
index e2cee5fb63c65..3d0085b245f60 100644
--- a/script/ci-release-build.js
+++ b/script/ci-release-build.js
@@ -14,7 +14,9 @@ const circleCIJobs = [
   'linux-arm-publish',
   'linux-arm64-publish',
   'linux-ia32-publish',
-  'linux-x64-publish'
+  'linux-x64-publish',
+  'mas-publish',
+  'osx-publish'
 ]
 
 const vstsJobs = [
diff --git a/spec/api-app-spec.js b/spec/api-app-spec.js
index 661295f619702..7d9b84ea5f93d 100644
--- a/spec/api-app-spec.js
+++ b/spec/api-app-spec.js
@@ -468,9 +468,6 @@ describe('app module', () => {
   })
 
   describe('app.get/setLoginItemSettings API', function () {
-    // allow up to three retries to account for flaky mas results
-    this.retries(3)
-
     const updateExe = path.resolve(path.dirname(process.execPath), '..', 'Update.exe')
     const processStartArgs = [
       '--processStart', `"${path.basename(process.execPath)}"`,
@@ -493,34 +490,26 @@ describe('app module', () => {
 
     it('sets and returns the app as a login item', done => {
       app.setLoginItemSettings({ openAtLogin: true })
-      // Wait because login item settings are not applied immediately in MAS build
-      const delay = process.mas ? 250 : 0
-      setTimeout(() => {
-        expect(app.getLoginItemSettings()).to.deep.equal({
-          openAtLogin: true,
-          openAsHidden: false,
-          wasOpenedAtLogin: false,
-          wasOpenedAsHidden: false,
-          restoreState: false
-        })
-        done()
-      }, delay)
+      expect(app.getLoginItemSettings()).to.deep.equal({
+        openAtLogin: true,
+        openAsHidden: false,
+        wasOpenedAtLogin: false,
+        wasOpenedAsHidden: false,
+        restoreState: false
+      })
+      done()
     })
 
     it('adds a login item that loads in hidden mode', done => {
       app.setLoginItemSettings({ openAtLogin: true, openAsHidden: true })
-      // Wait because login item settings are not applied immediately in MAS build
-      const delay = process.mas ? 250 : 0
-      setTimeout(() => {
-        expect(app.getLoginItemSettings()).to.deep.equal({
-          openAtLogin: true,
-          openAsHidden: process.platform === 'darwin' && !process.mas, // Only available on macOS
-          wasOpenedAtLogin: false,
-          wasOpenedAsHidden: false,
-          restoreState: false
-        })
-        done()
-      }, delay)
+      expect(app.getLoginItemSettings()).to.deep.equal({
+        openAtLogin: true,
+        openAsHidden: process.platform === 'darwin' && !process.mas, // Only available on macOS
+        wasOpenedAtLogin: false,
+        wasOpenedAsHidden: false,
+        restoreState: false
+      })
+      done()
     })
 
     it('correctly sets and unsets the LoginItem', function () {
@@ -534,7 +523,7 @@ describe('app module', () => {
     })
 
     it('correctly sets and unsets the LoginItem as hidden', function () {
-      if (process.platform !== 'darwin' || process.mas) this.skip()
+      if (process.platform !== 'darwin') this.skip()
 
       expect(app.getLoginItemSettings().openAtLogin).to.be.false()
       expect(app.getLoginItemSettings().openAsHidden).to.be.false()
diff --git a/vsts.yml b/vsts.yml
deleted file mode 100644
index 736973f878043..0000000000000
--- a/vsts.yml
+++ /dev/null
@@ -1,399 +0,0 @@
-# The config expects the following environment variables to be set:
-#  - "Custom.UseArtifacts.BuildId" aka "CUSTOM_USEARTIFACTS_BUILDID"
-#      Set it to a build number, e.g. 15912, to download artifacts
-#      from that build and only run the tests, instead of building from scratch.
-#  - "ELECTRON_RELEASE" Set it to '1' upload binaries on success.
-#  - "GN_CONFIG" Full path to a build config, e.g. '//electron/build/args/testing.gn'.
-#  - "GN_EXTRA_ARGS" Additional gn args, e.g. 'is_mas_build=true'.
-#  - "NOTIFY_SLACK" Set it to '1' to enable Slack notifications.
-#  - "RUN_TESTS" Set it to '1' to run Electron's tests.
-#  - "UPLOAD_TO_S3" Set it to '1' upload a release to the S3 bucket.
-#      Otherwise the release will be uploaded to the Github Releases.
-#      (The value is only checked if "ELECTRON_RELEASE" is defined.)
-#
-# The publishing scripts expect access tokens to be defined as env vars,
-# but those are not covered here.
-#
-# VSTS docs on variables:
-# https://docs.microsoft.com/en-us/azure/devops/pipelines/process/variables
-
-jobs:
-- job: build
-  displayName: Build
-  # Build Electron only if we are NOT going to use artifacts produced by a different build.
-  condition: eq(variables['Custom.UseArtifacts.BuildId'], '')
-  timeoutInMinutes: 120
-  variables:
-    CI: true
-  steps:
-
-  - bash: |
-      git clean -fdx
-    displayName: Clean unneeded git directories
-    timeoutInMinutes: 2
-
-  - task: CopyFiles@2
-    displayName: 'Copy Files to: src/electron'
-    inputs:
-      TargetFolder: src/electron
-    timeoutInMinutes: 2
-
-  - bash: |
-      export PATH="$PATH:/Users/electron/depot_tools"
-      echo "##vso[task.setvariable variable=PATH]$PATH"
-      export GIT_CACHE_PATH="/Users/electron/libcc_cache"
-      if [ "$ELECTRON_RELEASE" == "1" ]; then
-        GCLIENT_EXTRA_ARGS='--custom-var=checkout_boto=True --custom-var=checkout_requests=True'
-      fi
-
-      set -ex
-      gclient config \
-        --name "src/electron" \
-        --unmanaged \
-        $GCLIENT_EXTRA_ARGS \
-        "https://github.com/electron/electron"
-      gclient sync --with_branch_heads --with_tags
-      cd src
-      export CHROMIUM_BUILDTOOLS_PATH=`pwd`/buildtools
-      echo "##vso[task.setvariable variable=CHROMIUM_BUILDTOOLS_PATH]`pwd`/buildtools"
-    displayName: gclient sync
-    timeoutInMinutes: 25  # Usually takes about 10-15 minutes.
-
-  - bash: |
-      cd src
-      export SCCACHE_BINARY="`pwd`/electron/external_binaries/sccache"
-      "$SCCACHE_BINARY" --start-server
-      echo "##vso[task.setvariable variable=SCCACHE_BINARY]$SCCACHE_BINARY"
-      "$SCCACHE_BINARY" -s
-      echo "GN gen for: $GN_CONFIG"
-      gn gen out/Default --args='import("'$GN_CONFIG'") cc_wrapper="'"$SCCACHE_BINARY"'"'" $GN_EXTRA_ARGS"
-    env:
-      AWS_ACCESS_KEY_ID: $(SCCACHE_AWS_ACCESS_KEY)
-      AWS_SECRET_ACCESS_KEY: $(SCCACHE_AWS_SECRET)
-    displayName: GN gen with sccache
-    condition: and(succeeded(), ne(variables['ELECTRON_RELEASE'], '1'))
-    timeoutInMinutes: 1  # Shouldn't take more than 10 seconds.
-
-  - bash: |
-      cd src
-      echo "GN gen for: $GN_CONFIG"
-      gn gen out/Default --args='import("'$GN_CONFIG'")'" $GN_EXTRA_ARGS"
-    displayName: GN gen without sccache
-    condition: and(succeeded(), eq(variables['ELECTRON_RELEASE'], '1'))
-    timeoutInMinutes: 1  # Shouldn't take more than 10 seconds.
-
-  - bash: |
-      cd src
-      ninja -C out/Default electron:electron_app
-    displayName: Ninja build app
-    timeoutInMinutes: 100  # Can take up to 80 minutes without compiler cache.
-
-  - bash: |
-      cd src
-      ninja -C out/Default third_party/electron_node:headers
-    displayName: Build Node.js headers for testing
-    timeoutInMinutes: 1  # Usually takes less than 10 seconds.
-
-  - bash: |
-      cd src
-      gn gen out/ffmpeg --args='import("//electron/build/args/ffmpeg.gn") cc_wrapper="'"$SCCACHE_PATH"'"'" $GN_EXTRA_ARGS"
-      ninja -C out/ffmpeg electron:electron_ffmpeg_zip
-    displayName: Non proprietary ffmpeg build
-    condition: and(succeeded(), or(eq(variables['RUN_TESTS'], '1'), eq(variables['ELECTRON_RELEASE'], '1')))
-    timeoutInMinutes: 2  # Usually takes less than 30 seconds.
-
-  - bash: |
-      cd src
-      # Build needed dump_syms executable
-      ninja -C out/Default third_party/breakpad:dump_syms
-
-      # TODO(alexeykuzmin): Explicitly pass an out folder path to the scripts.
-      export ELECTRON_OUT_DIR=Default
-
-      electron/script/dump-symbols.py -d "$PWD/out/Default/breakpad_symbols"
-      electron/script/zip-symbols.py
-    displayName: Collect symbols
-    condition: and(succeeded(), eq(variables['ELECTRON_RELEASE'], '1'))
-    timeoutInMinutes: 5  # Usually takes less than two.
-
-  - bash: |
-      "$SCCACHE_BINARY" --stop-server
-    displayName: Check sccache stats after build
-    condition: and(succeeded(), ne(variables['ELECTRON_RELEASE'], '1'))
-    timeoutInMinutes: 1
-
-  - bash: |
-      cd src
-      ninja -C out/Default electron:electron_dist_zip
-    displayName: Build dist zip
-    timeoutInMinutes: 2  # Usually takes less than 20 seconds.
-
-  - bash: |
-      cd src
-      ninja -C out/Default electron:electron_chromedriver_zip
-    displayName: Build chromedriver and zip
-    timeoutInMinutes: 3  # Normally less than one minute.
-
-  - bash: |
-      cd src
-      ninja -C out/Default electron:electron_mksnapshot_zip
-    displayName: Build mksnapshot and zip
-    timeoutInMinutes: 1  # Normally less than 10 seconds.
-
-  - bash: |
-      cd src/electron
-      npm run create-typescript-definitions
-    displayName: Generate type declarations
-    condition: and(succeeded(), eq(variables['ELECTRON_RELEASE'], '1'))
-    timeoutInMinutes: 2  # Normally takes about 10-15 seconds.
-
-  - bash: |
-      cd src/electron
-
-      export ELECTRON_OUT_DIR=Default
-      export ELECTRON_S3_BUCKET="$(s3_bucket)"
-      export ELECTRON_S3_ACCESS_KEY="$(s3_access_key)"
-      export ELECTRON_S3_SECRET_KEY="$(s3_secret_key)"
-      export ELECTRON_GITHUB_TOKEN="$(github_token)"
-
-      if [ "$UPLOAD_TO_S3" == "1" ]; then
-        echo 'Uploading Electron release distribution to s3'
-        script/upload.py --upload_to_s3
-      else
-        echo 'Uploading Electron release distribution to Github releases'
-        script/upload.py
-      fi
-    displayName: Upload distribution
-    condition: and(succeeded(), eq(variables['ELECTRON_RELEASE'], '1'))
-    timeoutInMinutes: 5  # Normally takes about two minutes.
-
-  - task: PublishBuildArtifacts@1
-    displayName: Publish Build Artifacts (application zip)
-    inputs:
-      PathtoPublish: '$(System.DefaultWorkingDirectory)/src/out/Default/dist.zip'
-      ArtifactName: Default
-    timeoutInMinutes: 2  # The file is relatively big, so it takes about 20 seconds.
-
-  - task: PublishBuildArtifacts@1
-    displayName: Publish Build Artifacts (Node.js headers)
-    inputs:
-      PathtoPublish: '$(System.DefaultWorkingDirectory)/src/out/Default/gen/node_headers.tar.gz'
-      ArtifactName: Default
-    timeoutInMinutes: 1
-
-  - task: PublishBuildArtifacts@1
-    displayName: Publish Build Artifacts (chromedriver.zip)
-    inputs:
-      PathtoPublish: '$(System.DefaultWorkingDirectory)/src/out/Default/chromedriver.zip'
-      ArtifactName: Default
-    timeoutInMinutes: 1
-
-  - task: PublishBuildArtifacts@1
-    displayName: Publish Build Artifacts (mksnapshot.zip)
-    inputs:
-      PathtoPublish: '$(System.DefaultWorkingDirectory)/src/out/Default/mksnapshot.zip'
-      ArtifactName: Default
-    timeoutInMinutes: 1
-
-  - task: PublishBuildArtifacts@1
-    displayName: Publish Build Artifacts (ffmpeg.zip)
-    inputs:
-      PathtoPublish: '$(System.DefaultWorkingDirectory)/src/out/ffmpeg/ffmpeg.zip'
-      ArtifactName: Default
-    timeoutInMinutes: 1
-
-  - bash: |
-      echo $BUILD_SOURCEVERSION > revision
-    displayName: Save exact revision
-    timeoutInMinutes: 1
-
-  - task: PublishBuildArtifacts@1
-    displayName: Publish Build Artifacts (revision)
-    inputs:
-      PathtoPublish: '$(System.DefaultWorkingDirectory)/revision'
-      ArtifactName: Default
-    timeoutInMinutes: 1
-
-  # Notify about success only if we are supposed to, and we don't have to run tests first.
-  - bash: |
-      export BUILD_URL="${SYSTEM_TEAMFOUNDATIONCOLLECTIONURI}${SYSTEM_TEAMPROJECT}/_build/results?buildId=${BUILD_BUILDID}"
-      export MESSAGE="Build succeeded for *<$BUILD_URL|$BUILD_DEFINITIONNAME>* nightly build from *$BUILD_SOURCEBRANCHNAME*."
-      curl -g -H "Content-Type: application/json" -X POST \
-      -d "{\"text\": \"$MESSAGE\", \"attachments\": [{\"color\": \"good\",\"title\": \"$BUILD_DEFINITIONNAME nightly build results\",\"title_link\": \"$BUILD_URL\"}]}" $(slack_webhook)
-    displayName: Post Slack Notification on success
-    condition: and(succeeded(), and(eq(variables['NOTIFY_SLACK'], '1'), ne(variables['RUN_TESTS'], '1')))
-    timeoutInMinutes: 1
-
-  - bash: |
-      export BUILD_URL="${SYSTEM_TEAMFOUNDATIONCOLLECTIONURI}${SYSTEM_TEAMPROJECT}/_build/results?buildId=${BUILD_BUILDID}"
-      export MESSAGE="Build failed for *<$BUILD_URL|$BUILD_DEFINITIONNAME>* nightly build from *$BUILD_SOURCEBRANCHNAME*."
-      curl -g -H "Content-Type: application/json" -X POST \
-      -d "{\"text\": \"$MESSAGE\", \"attachments\": [{\"color\": \"#FC5C3C\",\"title\": \"$BUILD_DEFINITIONNAME nightly build results\",\"title_link\": \"$BUILD_URL\"}]}" $(slack_webhook)
-    displayName: 'Post Slack Notification on Failure'
-    condition: and(failed(), eq(variables['NOTIFY_SLACK'], '1'))
-    timeoutInMinutes: 1
-
-  - bash: |
-      rm -rf ..?* .[!.]* *
-    condition: always()
-    displayName: 'Cleanup directories'
-
-- job: run_tests
-  displayName: Run Tests
-  dependsOn: build
-  # Run this job only if we are supposed to run the tests,
-  # and we have an Electron built either in the previous job or in a different job, defined by a user.
-  condition: and(eq(variables['RUN_TESTS'], '1'), or(succeeded(), ne(variables['Custom.UseArtifacts.BuildId'], '')))
-  pool:
-    vmImage: 'macOS-10.13'
-  timeoutInMinutes: 20
-  variables:
-    CI: true
-  steps:
-
-  - task: CopyFiles@2
-    displayName: Copy Electron sources to "src/electron"
-    inputs:
-      TargetFolder: src/electron
-    timeoutInMinutes: 1
-
-  # Use Electron built in the current job, if a user didn't specify a build id.
-  - task: DownloadBuildArtifacts@0
-    displayName: Download build artifacts from the current build
-    inputs:
-      buildType: 'current'
-      artifactName: Default
-    condition: and(succeeded(), eq(variables['Custom.UseArtifacts.BuildId'], ''))
-    timeoutInMinutes: 1
-
-  # Use Electron built in a different job.
-  - task: DownloadBuildArtifacts@0
-    displayName: Download build artifacts from a build specified by user
-    inputs:
-      buildType: 'specific'
-      project: $(System.TeamProjectId)
-      pipeline: $(Build.DefinitionName)
-      buildVersionToDownload: 'specific'
-      buildId: $(Custom.UseArtifacts.BuildId)
-      artifactName: Default
-    condition: and(succeeded(), ne(variables['Custom.UseArtifacts.BuildId'], ''))
-    timeoutInMinutes: 1
-
-  - bash: |
-      TESTS_REVISION=$BUILD_SOURCEVERSION
-      SOURCES_REVISION=`cat ${SYSTEM_ARTIFACTSDIRECTORY}/Default/revision`
-      if [ $TESTS_REVISION != $SOURCES_REVISION ]; then
-        echo "$TESTS_REVISION != $SOURCES_REVISION"
-        exit 1
-      fi
-    displayName: Check if revisions of build sources and test sources match
-    timeoutInMinutes: 1
-
-  - task: ExtractFiles@1
-    displayName: Extract Electron app
-    inputs:
-      archiveFilePatterns: $(System.ArtifactsDirectory)/Default/dist.zip
-      destinationFolder: src/out/Default
-    timeoutInMinutes: 1
-
-  - task: ExtractFiles@1
-    displayName: Extract ffmpeg
-    inputs:
-      archiveFilePatterns: $(System.ArtifactsDirectory)/Default/ffmpeg.zip
-      destinationFolder: src/out/ffmpeg
-    timeoutInMinutes: 1
-
-  - task: ExtractFiles@1
-    displayName: Extract mksnapshot
-    inputs:
-      archiveFilePatterns: $(System.ArtifactsDirectory)/Default/mksnapshot.zip
-      destinationFolder: src/out/mksnapshot
-    timeoutInMinutes: 1
-
-  - task: CopyFiles@2
-    displayName: 'Copy Files to: src/out/Default'
-    inputs:
-      SourceFolder: src/out/mksnapshot
-      TargetFolder: src/out/Default
-      OverWrite: true
-    timeoutInMinutes: 1
-
-  - task: ExtractFiles@1
-    displayName: Extract Node.js headers
-    inputs:
-      archiveFilePatterns: $(System.ArtifactsDirectory)/Default/node_headers.tar.gz
-      destinationFolder: src/out/Default/gen
-    timeoutInMinutes: 1
-
-  - task: NodeTool@0
-    displayName: Install Node.js 10.x
-    inputs:
-      versionSpec: '10.x'
-    timeoutInMinutes: 2  # Should take less than a minute.
-
-  - bash: |
-      cd src/electron
-      npm install
-    displayName: Install Node.js modules
-    timeoutInMinutes: 4  # Should take about 30 seconds.
-
-  - bash: |
-      cd src
-      python electron/script/verify-ffmpeg.py --source-root "$PWD" --build-dir out/Default --ffmpeg-path out/ffmpeg
-    displayName: Verify non proprietary ffmpeg
-    timeoutInMinutes: 5
-
-  - bash: |
-      cd src
-      python electron/script/verify-mksnapshot.py --source-root "$PWD" --build-dir out/Default
-    displayName: Verify mksnapshot
-    timeoutInMinutes: 5
-
-  - bash: |
-      if pgrep Electron; then
-        killall Electron
-      fi
-      rm -rf ~/Library/Saved\ Application\ State/com.github.electron.savedState
-      rm -rf ~/Library/Application\ Support/Electron
-    displayName: Make sure Electron isn't running from previous tests
-    timeoutInMinutes: 1
-
-  - bash: |
-      export ELECTRON_OUT_DIR=Default
-      (cd src/electron && npm run test -- --ci)
-    displayName: Run Electron test suite
-    timeoutInMinutes: 10
-
-  - bash: |
-      cd src
-      if [ ! -s "$MOCHA_FILE" ]; then
-        exit 1
-      fi
-    displayName: Check test results existence
-    timeoutInMinutes: 1
-
-  - task: PublishTestResults@2
-    displayName: Publish Test Results
-    inputs:
-      testResultsFiles: '*.xml'
-      searchFolder: '$(System.DefaultWorkingDirectory)/src/junit/'
-    condition: and(always(), eq(variables['MOCHA_FILE'], 'junit/test-results.xml'))
-    timeoutInMinutes: 1
-
-  - bash: |
-      export BUILD_URL="${SYSTEM_TEAMFOUNDATIONCOLLECTIONURI}${SYSTEM_TEAMPROJECT}/_build/results?buildId=${BUILD_BUILDID}"
-      export MESSAGE="Build failed for *<$BUILD_URL|$BUILD_DEFINITIONNAME>* nightly build from *$BUILD_SOURCEBRANCHNAME*."
-      curl -g -H "Content-Type: application/json" -X POST \
-      -d "{\"text\": \"$MESSAGE\", \"attachments\": [{\"color\": \"#FC5C3C\",\"title\": \"$BUILD_DEFINITIONNAME nightly build results\",\"title_link\": \"$BUILD_URL\"}]}" $(slack_webhook)
-    displayName: Post Slack Notification on failure
-    condition: and(failed(), eq(variables['NOTIFY_SLACK'], '1'))
-    timeoutInMinutes: 1
-
-  - bash: |
-      export BUILD_URL="${SYSTEM_TEAMFOUNDATIONCOLLECTIONURI}${SYSTEM_TEAMPROJECT}/_build/results?buildId=${BUILD_BUILDID}"
-      export MESSAGE="Build succeeded for *<$BUILD_URL|$BUILD_DEFINITIONNAME>* nightly build from *$BUILD_SOURCEBRANCHNAME*."
-      curl -g -H "Content-Type: application/json" -X POST \
-      -d "{\"text\": \"$MESSAGE\", \"attachments\": [{\"color\": \"good\",\"title\": \"$BUILD_DEFINITIONNAME nightly build results\",\"title_link\": \"$BUILD_URL\"}]}" $(slack_webhook)
-    displayName: Post Slack Notification on success
-    condition: and(succeeded(), eq(variables['NOTIFY_SLACK'], '1'))
-    timeoutInMinutes: 1