Explicitly specify the ui::Compositor to DelegatedFrameHost

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index d75bbcebcbf063366004be10f09c48a1f1b86c45..6b8effd03710cbb14e9f78317c5cbadc7b526d91 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -2245,6 +2245,11 @@ void RenderWidgetHostViewAura::OnHostMoved(const aura::WindowTreeHost* host,
   UpdateScreenInfo(window_);
 }
 
+void RenderWidgetHostViewAura::OnHostCompositorWillBeDestroyed(
+    const aura::WindowTreeHost* host) {
+  delegated_frame_host_->ResetCompositor();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewAura, private:
 
@@ -2519,7 +2524,7 @@ void RenderWidgetHostViewAura::AddedToRootWindow() {
         reinterpret_cast<HWND>(GetNativeViewId()));
 #endif
 
-  delegated_frame_host_->AddedToWindow();
+  delegated_frame_host_->SetCompositor(window_->GetHost()->compositor());
 }
 
 void RenderWidgetHostViewAura::RemovingFromRootWindow() {
@@ -2531,7 +2536,7 @@ void RenderWidgetHostViewAura::RemovingFromRootWindow() {
   DetachFromInputMethod();
 
   window_->GetHost()->RemoveObserver(this);
-  delegated_frame_host_->RemovingFromWindow();
+  delegated_frame_host_->ResetCompositor();
 
 #if defined(OS_WIN)
   // Update the legacy window's parent temporarily to the desktop window. It
@@ -2583,11 +2588,6 @@ SkColorType RenderWidgetHostViewAura::PreferredReadbackFormat() {
 ////////////////////////////////////////////////////////////////////////////////
 // DelegatedFrameHost, public:
 
-ui::Compositor* RenderWidgetHostViewAura::GetCompositor() const {
-  aura::WindowTreeHost* host = window_->GetHost();
-  return host ? host->compositor() : NULL;
-}
-
 ui::Layer* RenderWidgetHostViewAura::GetLayer() {
   return window_->layer();
 }