This patch will add conditional code to use the prerendered version of Activity Stream if the prerendered pref is true.

If this can land before the activity stream prerender export, there'll be different patches needed for the all_files_referenced test

This could land before, but I'd have to set the default state of the pref to false (and we could change it back to true in the export)

Ok, I've updated this patch to remove the unreferenced file, so it should be good to go

Comment on attachment 8906681 [details] Bug 1398819 - Turn on prerendered version of activity stream in aboutNewTabService https://reviewboard.mozilla.org/r/178400/#review183752 I believe the always toggling in pref change is undesired. ::: browser/components/newtab/aboutNewTabService.js:28 (Diff revision 3) > > const IS_MAIN_PROCESS = Services.appinfo.processType === Services.appinfo.PROCESS_TYPE_DEFAULT; > > // Pref that tells if activity stream is enabled > const PREF_ACTIVITY_STREAM_ENABLED = "browser.newtabpage.activity-stream.enabled"; > +const PREF_ACTIVITY_STREAM_PRERENDERED_ENABLED = "browser.newtabpage.activity-stream.prerender"; one says "PRERENDERED_ENABLED" the other says "prerender" and another says `_activityStreamPrerendered` … oh well :p ::: browser/components/newtab/aboutNewTabService.js:94 (Diff revision 3) > > observe(subject, topic, data) { > switch (topic) { > case "nsPref:changed": > + this.toggleActivityStream(); > + Services.obs.notifyObservers(null, "newtab-url-changed", ABOUT_URL); Was this intended? Seems to always toggle then toggle again? ::: browser/components/newtab/aboutNewTabService.js:101 (Diff revision 3) > - if (this.toggleActivityStream()) { > + if (this.toggleActivityStream()) { > - Services.obs.notifyObservers(null, "newtab-url-changed", ABOUT_URL); > + Services.obs.notifyObservers(null, "newtab-url-changed", ABOUT_URL); > - } > + } > + } else if (data === PREF_ACTIVITY_STREAM_PRERENDERED_ENABLED) { > + this._activityStreamPrerendered = Services.prefs.getBoolPref(PREF_ACTIVITY_STREAM_PRERENDERED_ENABLED); > + Services.obs.notifyObservers(null, "newtab-default-url-changed"); Any reason not to just reuse "newtab-url-changed"? ::: browser/components/newtab/aboutNewTabService.js:158 (Diff revision 3) > get defaultURL() { > if (this.activityStreamEnabled) { > + if (this.activityStreamPrerendered) { > + return this.activityStreamPrerenderedURL; > + } > return this.activityStreamURL; nit: could just make this a return with conditional ternary operator

Comment on attachment 8906681 [details] Bug 1398819 - Turn on prerendered version of activity stream in aboutNewTabService https://reviewboard.mozilla.org/r/178400/#review183780 ::: browser/components/newtab/aboutNewTabService.js:101 (Diff revision 3) > - if (this.toggleActivityStream()) { > + if (this.toggleActivityStream()) { > - Services.obs.notifyObservers(null, "newtab-url-changed", ABOUT_URL); > + Services.obs.notifyObservers(null, "newtab-url-changed", ABOUT_URL); > - } > + } > + } else if (data === PREF_ACTIVITY_STREAM_PRERENDERED_ENABLED) { > + this._activityStreamPrerendered = Services.prefs.getBoolPref(PREF_ACTIVITY_STREAM_PRERENDERED_ENABLED); > + Services.obs.notifyObservers(null, "newtab-default-url-changed"); URL changed seems to be for the actual newtab url, i.e. "about:newtab", which is slightly different from the defaultUrl that backs it

Comment on attachment 8906681 [details] Bug 1398819 - Turn on prerendered version of activity stream in aboutNewTabService https://reviewboard.mozilla.org/r/178400/#review183810 Just some test cleanup (to correctly `cleanup` ;)) ::: browser/components/newtab/tests/xpcshell/test_AboutNewTabService.js:96 (Diff revision 4) > + await new Promise(resolve => { > + Services.obs.addObserver(function observer(aSubject, aTopic, aData) { > + Services.obs.removeObserver(observer, aTopic); > + resolve(); > + }, "newtab-url-changed"); > + Services.prefs.setBoolPref("browser.newtabpage.activity-stream.prerender", false); Looks like you can now just use `nextChangeNotificationPromise` probably like: ```js const notificationPromise = nextChangeNotificationPromise("about:newtab"); Services.prefs.setBoolPref("browser.newtabpage.activity-stream.prerender", false); ``` Also, we should be cleaning up these pref changes in `cleanup` at top. And looks like it's cleaning up incorrectly by setting activity stream to false. Probably should just be doing `Services.prefs.clearUserPref`

Pushed by edilee@gmail.com: https://hg.mozilla.org/integration/autoland/rev/8475a8df9f16 Turn on prerendered version of activity stream in aboutNewTabService r=Mardak