Add the 'config-enable-glean' Rollup option

Glean is disabled by default when building the core-addon.
The config-enable-glean option enables Glean. Note that,
if Glean is not initialized, no metric recording happens,
even if the Glean specific metrics APIs are called.

.eslintrc.cjs

@@ -22,6 +22,7 @@ module.exports = {
     __DISABLE_REMOTE_SETTINGS__: false,
     __DISABLE_LOCALE_CHECK__: false,
     __ENABLE_DATA_SUBMISSION__: false,
+    __ENABLE_GLEAN__: false,
     __WEBSITE_URL__: false,
   },
   overrides: [

core-addon/DataCollection.js

@@ -25,6 +25,11 @@ export default class DataCollection {
    *        Whether or not user has enrolled in the platform.
    */
   initialize(userEnrolled) {
+    if (!__ENABLE_GLEAN__) {
+      console.warn("DataCollection - Glean disabled by the build configuration.");
+      return;
+    }
+
     // Initialize Glean. Note that we always set 'uploadEnabled=true' if user
     // consented to join Rally. Upload is always enabled unless the web-extension
     // is uninstalled.

rollup.config.addon.js

@@ -29,6 +29,9 @@ export default (cliArgs) => {
         // to enable it for testing until https://github.com/mozilla-rally/core-addon/issues/304
         // is fixed.
         __ENABLE_DATA_SUBMISSION__: !!cliArgs["config-enable-data-submission"],
+        // In order to ease the integration, Glean will be embedded in the code but disabled
+        // until the integration is fully complete.
+        __ENABLE_GLEAN__: !!cliArgs["config-enable-glean"],
         __WEBSITE_URL__: cliArgs['config-website'] ?
           `'${cliArgs['config-website']}'` :
           "'https://rally.mozilla.org'",

tests/hooks.cjs

@@ -18,6 +18,7 @@ exports.mochaHooks = {
     // TODO: remove the next line once https://github.com/mozilla-rally/core-addon/issues/304
     // is merged.
     global.__ENABLE_DATA_SUBMISSION__ = true;
+    global.__ENABLE_GLEAN__ = true;
   },
   afterAll() {
     chrome.flush();
@@ -26,5 +27,6 @@ exports.mochaHooks = {
     // TODO: remove the next line once https://github.com/mozilla-rally/core-addon/issues/304
     // is merged.
     delete global.__ENABLE_DATA_SUBMISSION__;
+    delete global.__ENABLE_GLEAN__;
   },
 };