cast: support cursor rendering for tab capture

content/public/browser/render_widget_host_view_frame_subscriber.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_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_FRAME_SUBSCRIBER_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_FRAME_SUBSCRIBER_H_
 
 #include "base/callback.h"
 #include "base/time/time.h"
 
@@ skipping 23 matching lines @@
   // Called when a captured frame is available or the frame is no longer
   // needed by the platform layer.
   //
   // If |frame_captured| is true then frame provided contains valid content and
   // |timestamp| is the time when the frame was painted.
   //
   // If |frame_captured| is false then the content in frame provided is
   // invalid. There was an error during the process of frame capture or the
   // platform layer is shutting down. |timestamp| is also invalid in this case.
   typedef base::Callback<void(base::TimeTicks /* timestamp */,
+                              gfx::Rect /* region_in_frame */,

[miu, 2015/10/20 02:12:44]

Need to document this in the comments.  Something like "location within the
VideoFrame where the captured content resides, with the remaining parts of the
VideoFrame blacked-out."

[Irfan, 2015/10/21 23:01:08]

Done.

                               bool /* frame_captured */)> DeliverFrameCallback;
 
   // Called when a new frame is going to be presented at time
   // |present_time| with |damage_rect| being the region of the frame that has
   // changed since the last frame. The implementation decides whether the
   // current frame should be captured or not.
   //
   // Return true if the current frame should be captured. If so, |storage|
   // will be set to hold an appropriately sized and allocated buffer into which
   // to copy the frame. The platform presenter will perform scaling and color
   // space conversion to fit into the output frame.
   //
   // Destination format is determined by |storage|, currently only
   // media::PIXEL_FORMAT_YV12 is supported. Platform layer will perform color
   // space conversion if needed.
   //
   // When the frame is available |callback| will be called. It is up to the
   // platform layer to decide when to deliver a captured frame.
   //
   // Return false if the current frame should not be captured.
   virtual bool ShouldCaptureFrame(const gfx::Rect& damage_rect,
                                   base::TimeTicks present_time,
                                   scoped_refptr<media::VideoFrame>* storage,
                                   DeliverFrameCallback* callback) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_FRAME_SUBSCRIBER_H_