Bug 1352877 - Clear the compositor map later during shutdown. r=mattwoodrow

gfx/layers/ipc/CompositorBridgeParent.cpp

@@ -313,17 +313,16 @@ CompositorBridgeParent::Setup()
   sCompositorMap = new CompositorMap;
 }
 
-void
-CompositorBridgeParent::Shutdown()
-{
-  MOZ_ASSERT(sCompositorMap);
-  MOZ_ASSERT(sCompositorMap->empty());
-  sCompositorMap = nullptr;
-}
-
 void
 CompositorBridgeParent::FinishShutdown()
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (sCompositorMap) {
+    MOZ_ASSERT(sCompositorMap->empty());
+    sCompositorMap = nullptr;
+  }
+
   // TODO: this should be empty by now...
   sIndirectLayerTrees.clear();
 }

gfx/layers/ipc/CompositorBridgeParent.h

@@ -576,12 +576,7 @@ protected:
   static void Setup();
 
   /**
-   * Destroys the compositor thread and global compositor map.
-   */
-  static void Shutdown();
-
-  /**
-   * Finish the shutdown operation on the compositor thread.
+   * Remaning cleanups after the compositore thread is gone.
    */
   static void FinishShutdown();
 

gfx/layers/ipc/CompositorThread.cpp

@@ -69,7 +69,6 @@ CompositorThreadHolder::DestroyCompositorThread(base::Thread* aCompositorThread)
 
   MOZ_ASSERT(!sCompositorThreadHolder, "We shouldn't be destroying the compositor thread yet.");
 
-  CompositorBridgeParent::Shutdown();
   delete aCompositorThread;
   sFinishedCompositorShutDown = true;
 }