Mus+Ash: Use standard cc mechanism for surface lifetime.

services/ui/ws/platform_display_delegate.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SERVICES_UI_WS_PLATFORM_DISPLAY_DELEGATE_H_
 #define SERVICES_UI_WS_PLATFORM_DISPLAY_DELEGATE_H_
 
 namespace gfx {
 class Size;
 }
@@ skipping 24 matching lines @@
   // Called when an event arrives.
   virtual void OnEvent(const ui::Event& event) = 0;
 
   // Called when the Display loses capture.
   virtual void OnNativeCaptureLost() = 0;
 
   // Signals that the metrics of this display's viewport has changed.
   virtual void OnViewportMetricsChanged(const ViewportMetrics& old_metrics,
                                         const ViewportMetrics& new_metrics) = 0;
 
-  // Called when a compositor frame is finished drawing.
-  virtual void OnCompositorFrameDrawn() = 0;
-
  protected:
   virtual ~PlatformDisplayDelegate() {}
 };
 
 }  // namespace ws
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_PLATFORM_DISPLAY_DELEGATE_H_