Define frame subscription interface and implementation on Mac

content/browser/renderer_host/render_widget_host_view_mac.h

 // Copyright (c) 2012 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_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 #include <list>
 #include <map>
@@ skipping 256 matching lines @@
   virtual BackingStore* AllocBackingStore(const gfx::Size& size) OVERRIDE;
   virtual void CopyFromCompositingSurface(
       const gfx::Rect& src_subrect,
       const gfx::Size& dst_size,
       const base::Callback<void(bool, const SkBitmap&)>& callback) OVERRIDE;
   virtual void CopyFromCompositingSurfaceToVideoFrame(
       const gfx::Rect& src_subrect,
       const scoped_refptr<media::VideoFrame>& target,
       const base::Callback<void(bool)>& callback) OVERRIDE;
   virtual bool CanCopyToVideoFrame() const OVERRIDE;
+  virtual bool CanSubscribeFrame() const OVERRIDE;
+  virtual void BeginFrameSubscription(
+      RenderWidgetHostViewFrameSubscriber* subscriber) OVERRIDE;
+  virtual void EndFrameSubscription() OVERRIDE;
   virtual void OnAcceleratedCompositingStateChange() OVERRIDE;
   virtual void OnAccessibilityNotifications(
       const std::vector<AccessibilityHostMsg_NotificationParams>& params
       ) OVERRIDE;
   virtual bool PostProcessEventForPluginIme(
       const NativeWebKeyboardEvent& event) OVERRIDE;
 
   // Exposed for testing.
   CONTENT_EXPORT AcceleratedPluginView* ViewForPluginWindowHandle(
       gfx::PluginWindowHandle window);
@@ skipping 131 matching lines @@
   bool allow_overlapping_views_;
 
   NSWindow* pepper_fullscreen_window() const {
     return pepper_fullscreen_window_;
   }
 
   RenderWidgetHostViewMac* fullscreen_parent_host_view() const {
     return fullscreen_parent_host_view_;
   }
 
+  RenderWidgetHostViewFrameSubscriber* frame_subscriber() const {
+    return frame_subscriber_.get();
+  }
+
  private:
   friend class RenderWidgetHostView;
   friend class RenderWidgetHostViewMacTest;
 
   // The view will associate itself with the given widget. The native view must
   // be hooked up immediately to the view hierarchy, or else when it is
   // deleted it will delete this out from under the caller.
   explicit RenderWidgetHostViewMac(RenderWidgetHost* widget);
 
   // Returns whether this render view is a popup (autocomplete window).
@@ skipping 64 matching lines @@
   //   pairs of (route_id, gpu_host_id).
   std::list<std::pair<int32, int32> > pending_swap_buffers_acks_;
 
   // The current composition character range and its bounds.
   ui::Range composition_range_;
   std::vector<gfx::Rect> composition_bounds_;
 
   // The current caret bounds.
   gfx::Rect caret_rect_;
 
+  // Subscriber that listens to frame presentation events.
+  scoped_ptr<RenderWidgetHostViewFrameSubscriber> frame_subscriber_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewMac);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_