Allow ui::Compositor to disable commits during tab-switch

content/browser/compositor/browser_compositor_view_mac.h

 // Copyright 2014 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 CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_VIEW_MAC_H_
 #define CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_VIEW_MAC_H_
 
 #include "ui/accelerated_widget_mac/accelerated_widget_mac.h"
 #include "ui/compositor/compositor.h"
 
@@ skipping 15 matching lines @@
 
   // Indicate that the recyclable compositor should be destroyed, and no future
   // compositors should be recycled.
   static void DisableRecyclingForShutdown();
 
   ui::Compositor* compositor() { return &compositor_; }
   ui::AcceleratedWidgetMac* accelerated_widget_mac() {
     return accelerated_widget_mac_.get();
   }
 
+  // Suspend will prevent the compositor from producing new frames. This should
+  // be called to avoid creating spurious frames while changing state.
+  // Compositors are created as suspended.
+  void Suspend();
+  void Unsuspend();
+
  private:
   BrowserCompositorMac();
 
   scoped_ptr<ui::AcceleratedWidgetMac> accelerated_widget_mac_;
   ui::Compositor compositor_;
+  scoped_refptr<ui::CompositorLock> compositor_suspended_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserCompositorMac);
 };
 
 // A class to keep around whenever a BrowserCompositorMac may be created.
 // While at least one instance of this class exists, a spare
 // BrowserCompositorViewCocoa will be kept around to be recycled so that the
 // next BrowserCompositorMac to be created will be be created quickly.
 class BrowserCompositorMacPlaceholder {
  public:
   BrowserCompositorMacPlaceholder();
   ~BrowserCompositorMacPlaceholder();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BrowserCompositorMacPlaceholder);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_VIEW_MAC_H_