Define frame subscription interface and implementation on Mac

content/browser/renderer_host/compositing_iosurface_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_ACCELERATED_COMPOSITING_VIEW_MAC_H
 #define CONTENT_BROWSER_RENDERER_HOST_ACCELERATED_COMPOSITING_VIEW_MAC_H
 
 #import <Cocoa/Cocoa.h>
 #import <QuartzCore/CVDisplayLink.h>
 #include <QuartzCore/QuartzCore.h>
@@ skipping 12 matching lines @@
 #include "ui/gfx/size.h"
 
 class IOSurfaceSupport;
 
 namespace gfx {
 class Rect;
 }
 
 namespace content {
 
+class RenderWidgetHostViewFrameSubscriber;
+
 // This class manages an OpenGL context and IOSurface for the accelerated
 // compositing code path. The GL context is attached to
 // RenderWidgetHostViewCocoa for blitting the IOSurface.
 class CompositingIOSurfaceMac {
  public:
   // Passed to Create() to specify the ordering of the surface relative to the
   // containing window.
   enum SurfaceOrder {
     SURFACE_ORDER_ABOVE_WINDOW,
     SURFACE_ORDER_BELOW_WINDOW
   };
 
   // Returns NULL if IOSurface support is missing or GL APIs fail. Specify in
   // |order| the desired ordering relationship of the surface to the containing
   // window.
   static CompositingIOSurfaceMac* Create(SurfaceOrder order);
   ~CompositingIOSurfaceMac();
 
   // Set IOSurface that will be drawn on the next NSView drawRect.
   void SetIOSurface(uint64 io_surface_handle,
                     const gfx::Size& size);
 
   // Blit the IOSurface at the upper-left corner of the |view|. If |view| window
   // size is larger than the IOSurface, the remaining right and bottom edges
   // will be white. |scaleFactor| is 1 in normal views, 2 in HiDPI views.
-  void DrawIOSurface(NSView* view, float scale_factor);
+  // |frame_subscriber| listens to this draw event and provides output buffer
+  // for copying this frame into.
+  void DrawIOSurface(NSView* view, float scale_factor,
+                     RenderWidgetHostViewFrameSubscriber* frame_subscriber);
 
   // Copy the data of the "live" OpenGL texture referring to this IOSurfaceRef
   // into |out|. The copied region is specified with |src_pixel_subrect| and
   // the data is transformed so that it fits in |dst_pixel_size|.
   // |src_pixel_subrect| and |dst_pixel_size| are not in DIP but in pixel.
   // Caller must ensure that |out| is allocated to dimensions that match
   // dst_pixel_size, with no additional padding.
   // |callback| is invoked when the operation is completed or failed.
   // Do no call this method again before |callback| is invoked.
   void CopyTo(const gfx::Rect& src_pixel_subrect,
@@ skipping 152 matching lines @@
 
   void CalculateVsyncParametersLockHeld(const CVTimeStamp* time);
 
   // Prevent from spinning on CGLFlushDrawable when it fails to throttle to
   // VSync frequency.
   void RateLimitDraws();
 
   void StartOrContinueDisplayLink();
   void StopDisplayLink();
 
+  // Copy current frame to |target| video frame. This method must be called
+  // within a CGL context. Returns a callback that should be called outside
+  // of the CGL context.
+  base::Closure CopyToVideoFrameInternal(
+      const gfx::Rect& src_subrect,
+      float src_scale_factor,
+      const scoped_refptr<media::VideoFrame>& target,
+      const base::Callback<void(bool)>& callback);
+
   // Two implementations of CopyTo() in synchronous and asynchronous mode.
   // These may copy regions smaller than the requested |src_pixel_subrect| if
   // the iosurface is smaller than |src_pixel_subrect|.
   bool SynchronousCopyTo(const gfx::Rect& src_pixel_subrect,
                          float src_scale_factor,
                          const gfx::Size& dst_pixel_size,
                          const SkBitmap& out);
   bool AsynchronousCopyTo(
       const gfx::Rect& src_pixel_subrect,
       float src_scale_factor,
@@ skipping 60 matching lines @@
   uint32 vsync_interval_denominator_;
 
   bool initialized_is_intel_;
   bool is_intel_;
   GLint screen_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_ACCELERATED_COMPOSITING_VIEW_MAC_H