Aura/ÜC: Drop frames on background tabs

content/browser/renderer_host/render_widget_host_view_aura.h

Index: content/browser/renderer_host/render_widget_host_view_aura.h
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.h b/content/browser/renderer_host/render_widget_host_view_aura.h
index f333eed33b0e013051235ce185ae8371b83f8618..ab27055ac9d370e0b293d9a8eeeebb9c2d6e29cc 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.h
+++ b/content/browser/renderer_host/render_widget_host_view_aura.h
@@ -20,6 +20,7 @@
 #include "cc/resources/texture_mailbox.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/browser/aura/image_transport_factory.h"
+#include "content/browser/renderer_host/delegated_frame_evictor.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 #include "content/browser/renderer_host/software_frame_manager.h"
 #include "content/common/content_export.h"
@@ -78,6 +79,7 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
       public ImageTransportFactoryObserver,
       public BrowserAccessibilityDelegate,
       public SoftwareFrameManagerClient,
+      public DelegatedFrameEvictorClient,
       public base::SupportsWeakPtr<RenderWidgetHostViewAura>,
       public cc::DelegatedFrameResourceCollectionClient {
  public:
@@ -388,6 +390,8 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
   FRIEND_TEST_ALL_PREFIXES(RenderWidgetHostViewAuraTest,
                            SkippedDelegatedFrames);
   FRIEND_TEST_ALL_PREFIXES(RenderWidgetHostViewAuraTest, OutputSurfaceIdChange);
+  FRIEND_TEST_ALL_PREFIXES(RenderWidgetHostViewAuraTest,
+                           DiscardDelegatedFrames);
 
   class WindowObserver;
   friend class WindowObserver;
@@ -527,6 +531,9 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
   void SendDelegatedFrameAck(uint32 output_surface_id);
   void SendReturnedDelegatedResources(uint32 output_surface_id);
 
+  // DelegatedFrameEvictorClient implementation.
+  virtual void EvictDelegatedFrame() OVERRIDE;
+
   // cc::DelegatedFrameProviderClient implementation.
   virtual void UnusedResourcesAreAvailable() OVERRIDE;
 
@@ -754,6 +761,7 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
     unsigned frame_id;
   };
   scoped_ptr<ReleasedFrameInfo> released_software_frame_;
+  scoped_ptr<DelegatedFrameEvictor> delegated_frame_evictor_;
 
   base::WeakPtrFactory<RenderWidgetHostViewAura> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewAura);