Backed out 2 changesets (bug 1532712) for mochitest failures at browser_policy_set_homepage.js on a CLOSED TREE.

Backed out changeset 1af088f5fc34 (bug 1532712)
Backed out changeset 5fb5272aec8e (bug 1532712)

browser/components/preferences/in-content/preferences.js

@@ -24,7 +24,7 @@ ChromeUtils.defineModuleGetter(this, "AMTelemetry",
 ChromeUtils.defineModuleGetter(this, "formAutofillParent",
                                "resource://formautofill/FormAutofillParent.jsm");
 
-var gLastCategory = {category: undefined, subcategory: undefined};
+var gLastHash = "";
 const gXULDOMParser = new DOMParser();
 
 var gCategoryInits = new Map();
@@ -34,27 +34,48 @@ function init_category_if_required(category) {
     throw "Unknown in-content prefs category! Can't init " + category;
   }
   if (categoryInfo.inited) {
-    return null;
+    return;
   }
-  return categoryInfo.init();
+  categoryInfo.init();
 }
 
 function register_module(categoryName, categoryObject) {
   gCategoryInits.set(categoryName, {
     inited: false,
-    async init() {
+    init() {
       let template = document.getElementById("template-" + categoryName);
       if (template) {
         // Replace the template element with the nodes from the parsed comment
         // string.
         let frag = MozXULElement.parseXULToFragment(template.firstChild.data);
 
-        await document.l10n.translateFragment(frag);
+        // Gather the to-be-translated elements so that we could pass them to
+        // l10n.translateElements() and get a translated promise.
+        // Here we loop through the first level elements (<hbox>/<groupbox>/<deck>/etc)
+        // because we know that they are not implemented by XBL bindings,
+        // so it's ok to get a reference of them before inserting the node
+        // to the DOM.
+        //
+        // If we don't have to worry about XBL, this can simply be
+        // let l10nUpdatedElements = Array.from(frag.querySelectorAll("[data-l10n-id]"))
+        //
+        // If we can get a translated promise after insertion, this can all be
+        // removed (see bug 1520659.)
+        let firstLevelElements = Array.from(frag.children);
 
         // Actually insert them into the DOM.
-        document.l10n.pauseObserving();
         template.replaceWith(frag);
-        document.l10n.resumeObserving();
+
+        let l10nUpdatedElements = [];
+        // Collect the elements from the newly inserted first level elements.
+        for (let el of firstLevelElements) {
+          l10nUpdatedElements = l10nUpdatedElements.concat(
+            Array.from(el.querySelectorAll("[data-l10n-id]")));
+        }
+
+        // Set a promise on the categoryInfo object that the highlight code can await on.
+        this.translated = document.l10n.translateElements(l10nUpdatedElements)
+          .then(() => this.translated = undefined);
 
         // Asks Preferences to update the attribute value of the entire
         // document again (this can be simplified if we could seperate the
@@ -69,7 +90,7 @@ function register_module(categoryName, categoryObject) {
 
 document.addEventListener("DOMContentLoaded", init_all, {once: true});
 
-async function init_all() {
+function init_all() {
   Preferences.forceEnableInstantApply();
 
   gSubDialog.init();
@@ -101,7 +122,7 @@ async function init_all() {
   maybeDisplayPoliciesNotice();
 
   window.addEventListener("hashchange", onHashChange);
-  await gotoPref();
+  gotoPref();
 
   let helpButton = document.getElementById("helpButton");
   let helpUrl = Services.urlFormatter.formatURLPref("app.support.baseURL") + "preferences";
@@ -143,7 +164,7 @@ function onHashChange() {
   gotoPref();
 }
 
-async function gotoPref(aCategory) {
+function gotoPref(aCategory) {
   let categories = document.getElementById("categories");
   const kDefaultCategoryInternalName = "paneGeneral";
   const kDefaultCategory = "general";
@@ -174,7 +195,7 @@ async function gotoPref(aCategory) {
 
   // Updating the hash (below) or changing the selected category
   // will re-enter gotoPref.
-  if (gLastCategory.category == category && !subcategory)
+  if (gLastHash == category && !subcategory)
     return;
 
   let item;
@@ -186,35 +207,26 @@ async function gotoPref(aCategory) {
     }
   }
 
-  if (gLastCategory.category || category != kDefaultCategoryInternalName || subcategory) {
+  try {
-    let friendlyName = internalPrefCategoryNameToFriendlyName(category);
+    init_category_if_required(category);
+  } catch (ex) {
+    Cu.reportError("Error initializing preference category " + category + ": " + ex);
+    throw ex;
+  }
+
+  let friendlyName = internalPrefCategoryNameToFriendlyName(category);
+  if (gLastHash || category != kDefaultCategoryInternalName || subcategory) {
     document.location.hash = friendlyName;
   }
-  // Need to set the gLastCategory before setting categories.selectedItem since
+  // Need to set the gLastHash before setting categories.selectedItem since
   // the categories 'select' event will re-enter the gotoPref codepath.
-  gLastCategory.category = category;
+  gLastHash = category;
-  gLastCategory.subcategory = subcategory;
   if (item) {
     categories.selectedItem = item;
   } else {
     categories.clearSelection();
   }
   window.history.replaceState(category, document.title);
-
-  try {
-    await init_category_if_required(category);
-  } catch (ex) {
-    Cu.reportError(new Error("Error initializing preference category " + category + ": " + ex));
-    throw ex;
-  }
-
-  // Bail out of this goToPref if the category
-  // or subcategory changed during async operation.
-  if (gLastCategory.category !== category ||
-      gLastCategory.subcategory !== subcategory) {
-    return;
-  }
-
   search(category, "data-category");
 
   let mainContent = document.querySelector(".main-content");
@@ -272,6 +284,7 @@ async function scrollAndHighlight(subcategory, category) {
     return;
   }
   let header = getClosestDisplayedHeader(element);
+  await gCategoryInits.get(category).translated;
 
   scrollContentTo(header);
   element.classList.add("spotlight");

dom/webidl/DocumentL10n.webidl

@@ -141,18 +141,6 @@ interface DocumentL10n {
    */
   [NewObject] Promise<void> translateElements(sequence<Element> aElements);
 
-  /**
-   * Pauses the MutationObserver set to observe
-   * localization related DOM mutations.
-   */
-  [Throws] void pauseObserving();
-
-  /**
-   * Resumes the MutationObserver set to observe
-   * localization related DOM mutations.
-   */
-  [Throws] void resumeObserving();
-
   /**
    * A promise which gets resolved when the initial DOM localization resources
    * fetching is complete and the initial translation of the DOM is finished.

intl/l10n/DocumentL10n.cpp

@@ -351,14 +351,6 @@ already_AddRefed<Promise> DocumentL10n::TranslateElements(
   return MaybeWrapPromise(promise);
 }
 
-void DocumentL10n::PauseObserving(ErrorResult& aRv) {
-  aRv = mDOMLocalization->PauseObserving();
-}
-
-void DocumentL10n::ResumeObserving(ErrorResult& aRv) {
-  aRv = mDOMLocalization->ResumeObserving();
-}
-
 class L10nReadyHandler final : public PromiseNativeHandler {
  public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS

intl/l10n/DocumentL10n.h

@@ -125,9 +125,6 @@ class DocumentL10n final : public nsIObserver,
   already_AddRefed<Promise> TranslateElements(
       const Sequence<OwningNonNull<Element>>& aElements, ErrorResult& aRv);
 
-  void PauseObserving(ErrorResult& aRv);
-  void ResumeObserving(ErrorResult& aRv);
-
   Promise* Ready();
 
   void TriggerInitialDocumentTranslation();

intl/l10n/mozIDOMLocalization.idl

@@ -25,10 +25,6 @@ interface mozIDOMLocalization : nsISupports
 
   void connectRoot(in Element aElement);
   void disconnectRoot(in Element aElement);
-
-  void pauseObserving();
-  void resumeObserving();
-
   Promise translateRoots();
   readonly attribute Promise ready;
 };