refactor: remove -new-contents-created event

Chromium expects us to take ownership of WebContents in AddNewContents,
we should not create V8 wrapper in WebContentsCreated, otherwise we
would have WebContents being managed by 2 unique_ptr at the same time.

atom/browser/api/atom_api_web_contents.cc

@@ -539,11 +539,10 @@ void WebContents::WebContentsCreated(content::WebContents* source_contents,
                                      const std::string& frame_name,
                                      const GURL& target_url,
                                      content::WebContents* new_contents) {
-  v8::Locker locker(isolate());
-  v8::HandleScope handle_scope(isolate());
-  // Create V8 wrapper for the |new_contents|.
-  auto wrapper = CreateAndTake(isolate(), new_contents, BROWSER_WINDOW);
-  Emit("-web-contents-created", wrapper, target_url, frame_name);
+  ChildWebContentsTracker::CreateForWebContents(new_contents);
+  auto* tracker = ChildWebContentsTracker::FromWebContents(new_contents);
+  tracker->url = target_url;
+  tracker->frame_name = frame_name;
 }
 
 void WebContents::AddNewContents(
@@ -553,17 +552,16 @@ void WebContents::AddNewContents(
     const gfx::Rect& initial_rect,
     bool user_gesture,
     bool* was_blocked) {
-  new ChildWebContentsTracker(new_contents.get());
+  auto* tracker = ChildWebContentsTracker::FromWebContents(new_contents.get());
+  DCHECK(tracker);
+
   v8::Locker locker(isolate());
   v8::HandleScope handle_scope(isolate());
-  // Note that the ownership of |new_contents| has already been claimed by
-  // the WebContentsCreated method, the release call here completes
-  // the ownership transfer.
-  auto api_web_contents = From(isolate(), new_contents.release());
-  DCHECK(!api_web_contents.IsEmpty());
+  auto api_web_contents =
+      CreateAndTake(isolate(), new_contents.release(), BROWSER_WINDOW);
   if (Emit("-add-new-contents", api_web_contents, disposition, user_gesture,
            initial_rect.x(), initial_rect.y(), initial_rect.width(),
-           initial_rect.height())) {
+           initial_rect.height(), tracker->url, tracker->frame_name)) {
     api_web_contents->DestroyWebContents(true /* async */);
   }
 }

atom/browser/atom_browser_client.cc

@@ -165,7 +165,7 @@ bool AtomBrowserClient::ShouldCreateNewSiteInstance(
     }
     auto* web_contents =
         content::WebContents::FromRenderFrameHost(render_frame_host);
-    if (!ChildWebContentsTracker::IsChildWebContents(web_contents)) {
+    if (!ChildWebContentsTracker::FromWebContents(web_contents)) {
       // Root WebContents should always create new process to make sure
       // native addons are loaded correctly after reload / navigation.
       // (Non-root WebContents opened by window.open() should try to

atom/browser/child_web_contents_tracker.h

@@ -5,19 +5,25 @@
 #ifndef ATOM_BROWSER_CHILD_WEB_CONTENTS_TRACKER_H_
 #define ATOM_BROWSER_CHILD_WEB_CONTENTS_TRACKER_H_
 
-#include "content/public/browser/web_contents_observer.h"
+#include <string>
+
+#include "content/public/browser/web_contents_user_data.h"
 
 namespace atom {
 
 // ChildWebContentsTracker tracks child WebContents
 // created by native `window.open()`
-class ChildWebContentsTracker : public content::WebContentsObserver {
- public:
-  explicit ChildWebContentsTracker(content::WebContents* web_contents);
-  static bool IsChildWebContents(content::WebContents* web_contents);
+struct ChildWebContentsTracker
+    : public content::WebContentsUserData<ChildWebContentsTracker> {
+  GURL url;
+  std::string frame_name;
+
+  explicit ChildWebContentsTracker(content::WebContents* web_contents) {}
+
+ private:
+  friend class content::WebContentsUserData<ChildWebContentsTracker>;
 
- protected:
-  void WebContentsDestroyed() override;
+  DISALLOW_COPY_AND_ASSIGN(ChildWebContentsTracker);
 };
 
 }  // namespace atom

filenames.gni

@@ -239,7 +239,6 @@ filenames = {
     "atom/browser/browser_mac.mm",
     "atom/browser/browser_win.cc",
     "atom/browser/browser_observer.h",
-    "atom/browser/child_web_contents_tracker.cc",
     "atom/browser/child_web_contents_tracker.h",
     "atom/browser/common_web_contents_delegate_mac.mm",
     "atom/browser/common_web_contents_delegate_views.cc",

lib/browser/api/browser-window.js

@@ -3,7 +3,6 @@
 const electron = require('electron')
 const { WebContentsView, TopLevelWindow } = electron
 const { BrowserWindow } = process.atomBinding('window')
-const v8Util = process.atomBinding('v8_util')
 const ipcMain = require('@electron/internal/browser/ipc-main-internal')
 
 Object.setPrototypeOf(BrowserWindow.prototype, TopLevelWindow.prototype)
@@ -32,25 +31,16 @@ BrowserWindow.prototype._init = function () {
       options, additionalFeatures, postData)
   })
 
-  this.webContents.on('-web-contents-created', (event, webContents, url,
-    frameName) => {
-    v8Util.setHiddenValue(webContents, 'url-framename', { url, frameName })
-  })
-
   // Create a new browser window for the native implementation of
   // "window.open", used in sandbox and nativeWindowOpen mode
   this.webContents.on('-add-new-contents', (event, webContents, disposition,
-    userGesture, left, top, width,
-    height) => {
-    const urlFrameName = v8Util.getHiddenValue(webContents, 'url-framename')
+    userGesture, left, top, width, height, url, frameName) => {
     if ((disposition !== 'foreground-tab' && disposition !== 'new-window' &&
-         disposition !== 'background-tab') || !urlFrameName) {
+         disposition !== 'background-tab')) {
       event.preventDefault()
       return
     }
 
-    const { url, frameName } = urlFrameName
-    v8Util.deleteHiddenValue(webContents, 'url-framename')
     const options = {
       show: true,
       x: left,

lib/browser/guest-view-manager.js

@@ -157,14 +157,6 @@ const createGuest = function (embedder, params) {
       }
     }
   })
-  guest.on('-web-contents-created', (...args) => {
-    if (guest.getLastWebPreferences().nativeWindowOpen === true) {
-      const embedder = getEmbedder(guestInstanceId)
-      if (embedder != null) {
-        embedder.emit('-web-contents-created', ...args)
-      }
-    }
-  })
 
   return guestInstanceId
 }