Bug 1176829 - Remove custom elements base element queue. r=smaug

dom/base/nsContentUtils.cpp

@@ -5230,7 +5230,6 @@ nsContentUtils::LeaveMicroTask()
   MOZ_ASSERT(NS_IsMainThread());
   if (--sMicroTaskLevel == 0) {
     PerformMainThreadMicroTaskCheckpoint();
-    nsDocument::ProcessBaseElementQueue();
   }
 }
 

dom/base/nsDocument.cpp

@@ -5895,29 +5895,6 @@ nsDocument::RegisterUnresolvedElement(Element* aElement, nsIAtom* aTypeName)
   return NS_OK;
 }
 
-namespace {
-
-class ProcessStackRunner final : public nsIRunnable
-{
-  ~ProcessStackRunner() {}
-public:
-  explicit ProcessStackRunner(bool aIsBaseQueue = false)
-    : mIsBaseQueue(aIsBaseQueue)
-  {
-  }
-  NS_DECL_ISUPPORTS
-  NS_IMETHOD Run() override
-  {
-    nsDocument::ProcessTopElementQueue(mIsBaseQueue);
-    return NS_OK;
-  }
-  bool mIsBaseQueue;
-};
-
-NS_IMPL_ISUPPORTS(ProcessStackRunner, nsIRunnable);
-
-} // namespace
-
 void
 nsDocument::EnqueueLifecycleCallback(nsIDocument::ElementCallbackType aType,
                                      Element* aCustomElement,
@@ -6019,10 +5996,7 @@ nsDocument::EnqueueLifecycleCallback(nsIDocument::ElementCallbackType aType,
 
     // A new element queue needs to be pushed if the queue at the
     // top of the stack is associated with another microtask level.
-    // Don't push a queue for the level 0 microtask (base element queue)
-    // because we don't want to process the queue until the
-    // microtask checkpoint.
-    bool shouldPushElementQueue = nsContentUtils::MicroTaskLevel() > 0 &&
+    bool shouldPushElementQueue =
       (!lastData || lastData->mAssociatedMicroTask <
          static_cast<int32_t>(nsContentUtils::MicroTaskLevel()));
 
@@ -6045,39 +6019,22 @@ nsDocument::EnqueueLifecycleCallback(nsIDocument::ElementCallbackType aType,
       // should be invoked prior to returning control back to script.
       // Create a script runner to process the top of the processing
       // stack as soon as it is safe to run script.
-      nsContentUtils::AddScriptRunner(new ProcessStackRunner());
+      nsCOMPtr<nsIRunnable> runnable =
+        NS_NewRunnableFunction(&nsDocument::ProcessTopElementQueue);
+      nsContentUtils::AddScriptRunner(runnable);
     }
   }
 }
 
 // static
 void
-nsDocument::ProcessBaseElementQueue()
-{
-  // Prevent re-entrance. Also, if a microtask checkpoint is reached
-  // and there is no processing stack to process, then we are done.
-  if (sProcessingBaseElementQueue || !sProcessingStack) {
-    return;
-  }
-
-  MOZ_ASSERT(nsContentUtils::MicroTaskLevel() == 0);
-  sProcessingBaseElementQueue = true;
-  nsContentUtils::AddScriptRunner(new ProcessStackRunner(true));
-}
-
-// static
-void
-nsDocument::ProcessTopElementQueue(bool aIsBaseQueue)
+nsDocument::ProcessTopElementQueue()
 {
   MOZ_ASSERT(nsContentUtils::IsSafeToRunScript());
 
   nsTArray<nsRefPtr<CustomElementData>>& stack = *sProcessingStack;
   uint32_t firstQueue = stack.LastIndexOf((CustomElementData*) nullptr);
 
-  if (aIsBaseQueue && firstQueue != 0) {
-    return;
-  }
-
   for (uint32_t i = firstQueue + 1; i < stack.Length(); ++i) {
     // Callback queue may have already been processed in an earlier
     // element queue or in an element queue that was popped
@@ -6095,7 +6052,6 @@ nsDocument::ProcessTopElementQueue(bool aIsBaseQueue)
   } else {
     // Don't pop sentinel for base element queue.
     stack.SetLength(1);
-    sProcessingBaseElementQueue = false;
   }
 }
 

dom/base/nsDocument.h

@@ -1303,7 +1303,7 @@ public:
                                         mozilla::dom::LifecycleCallbackArgs* aArgs = nullptr,
                                         mozilla::dom::CustomElementDefinition* aDefinition = nullptr) override;
 
-  static void ProcessTopElementQueue(bool aIsBaseQueue = false);
+  static void ProcessTopElementQueue();
 
   void GetCustomPrototype(int32_t aNamespaceID,
                           nsIAtom* aAtom,
@@ -1600,15 +1600,9 @@ private:
   // queue in the stack is the base element queue.
   static mozilla::Maybe<nsTArray<nsRefPtr<mozilla::dom::CustomElementData>>> sProcessingStack;
 
-  // Flag to prevent re-entrance into base element queue as described in the
-  // custom elements speicification.
-  static bool sProcessingBaseElementQueue;
-
   static bool CustomElementConstructor(JSContext* aCx, unsigned aArgc, JS::Value* aVp);
 
 public:
-  static void ProcessBaseElementQueue();
-
   // Enqueue created callback or register upgrade candidate for
   // newly created custom elements, possibly extending an existing type.
   // ex. <x-button>, <button is="x-button> (type extension)