Delay the DidComposite call in ClientLayerManager's destructor. (bug 1305829, r=mattwoodrow)

gfx/layers/client/ClientLayerManager.cpp

@@ -112,10 +112,6 @@ ClientLayerManager::ClientLayerManager(nsIWidget* aWidget)
 
 ClientLayerManager::~ClientLayerManager()
 {
-  if (mTransactionIdAllocator) {
-    TimeStamp now = TimeStamp::Now();
-    DidComposite(mLatestTransactionId, now, now);
-  }
   mMemoryPressureObserver->Destroy();
   ClearCachedResources();
   // Stop receiveing AsyncParentMessage at Forwarder.
@@ -137,6 +133,19 @@ ClientLayerManager::Destroy()
   // former will early-return if the later has already run.
   ClearCachedResources();
   LayerManager::Destroy();
+
+  if (mTransactionIdAllocator) {
+    // Make sure to notify the refresh driver just in case it's waiting on a
+    // pending transaction. Do this at the top of the event loop so we don't
+    // cause a paint to occur during compositor shutdown.
+    RefPtr<TransactionIdAllocator> allocator = mTransactionIdAllocator;
+    uint64_t id = mLatestTransactionId;
+
+    RefPtr<Runnable> task = NS_NewRunnableFunction([allocator, id] () -> void {
+      allocator->NotifyTransactionCompleted(id);
+    });
+    NS_DispatchToMainThread(task.forget());
+  }
 }
 
 int32_t

widget/nsBaseWidget.cpp

@@ -248,6 +248,7 @@ WidgetShutdownObserver::Unregister()
 void
 nsBaseWidget::Shutdown()
 {
+  RevokeTransactionIdAllocator();
   DestroyCompositor();
   FreeShutdownObserver();
 #if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
@@ -295,6 +296,23 @@ void nsBaseWidget::DestroyCompositor()
   }
 }
 
+// This prevents the layer manager from starting a new transaction during
+// shutdown.
+void
+nsBaseWidget::RevokeTransactionIdAllocator()
+{
+  if (!mLayerManager) {
+    return;
+  }
+
+  ClientLayerManager* clm = mLayerManager->AsClientLayerManager();
+  if (!clm) {
+    return;
+  }
+
+  clm->SetTransactionIdAllocator(nullptr);
+}
+
 void nsBaseWidget::ReleaseContentController()
 {
   if (mRootContentController) {
@@ -377,6 +395,7 @@ nsBaseWidget::~nsBaseWidget()
   }
 
   FreeShutdownObserver();
+  RevokeTransactionIdAllocator();
   DestroyLayerManager();
 
 #ifdef NOISY_WIDGET_LEAKS

widget/nsBaseWidget.h

@@ -643,6 +643,7 @@ protected:
   virtual void DestroyCompositor();
   void DestroyLayerManager();
   void ReleaseContentController();
+  void RevokeTransactionIdAllocator();
 
   void FreeShutdownObserver();