Explicitly specify the ui::Compositor to DelegatedFrameHost

ui/compositor/compositor.cc

Index: ui/compositor/compositor.cc
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index 0e917265415fd26e79e453e48160b41050ca6031..2363c7c3338e2d95356c0f6f52921e5101f6a482 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -175,6 +175,9 @@ Compositor::~Compositor() {
   CancelCompositorLock();
   DCHECK(!compositor_lock_);
 
+  FOR_EACH_OBSERVER(CompositorObserver, observer_list_,
+                    OnCompositingShuttingDown(this));
+
   if (root_layer_)
     root_layer_->SetCompositor(NULL);
 
@@ -299,25 +302,10 @@ scoped_refptr<CompositorVSyncManager> Compositor::vsync_manager() const {
 }
 
 void Compositor::AddObserver(CompositorObserver* observer) {
-#if defined(OS_MACOSX)
-  // Debugging instrumentation for crbug.com/401630.
-  // TODO(ccameron): remove this.
-  CHECK(observer);
-  if (!observer_list_.HasObserver(observer))
-    observer->observing_count_ += 1;
-#endif
-
   observer_list_.AddObserver(observer);
 }
 
 void Compositor::RemoveObserver(CompositorObserver* observer) {
-#if defined(OS_MACOSX)
-  // Debugging instrumentation for crbug.com/401630.
-  // TODO(ccameron): remove this.
-  if (observer_list_.HasObserver(observer))
-    observer->observing_count_ -= 1;
-#endif
-
   observer_list_.RemoveObserver(observer);
 }