HW Video: Make media::VideoFrame handle the sync point of the compositor as well as webgl

cc/resources/video_resource_updater.cc

 // Copyright 2013 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.
 
 #include "cc/resources/video_resource_updater.h"
 
 #include "base/bind.h"
 #include "cc/output/gl_renderer.h"
 #include "cc/resources/resource_provider.h"
 #include "gpu/GLES2/gl2extchromium.h"
@@ skipping 293 matching lines @@
         base::Bind(&RecycleResource, AsWeakPtr(), recycle_data));
   }
 
   external_resources.type = VideoFrameExternalResources::YUV_RESOURCE;
   return external_resources;
 }
 
 static void ReturnTexture(const scoped_refptr<media::VideoFrame>& frame,
                           uint32 sync_point,
                           bool lost_resource) {
-  frame->mailbox_holder()->sync_point = sync_point;
+  frame->AppendReleaseSyncPoint(sync_point);
 }
 
 VideoFrameExternalResources VideoResourceUpdater::CreateForHardwarePlanes(
     const scoped_refptr<media::VideoFrame>& video_frame) {
   media::VideoFrame::Format frame_format = video_frame->format();
 
   DCHECK_EQ(frame_format, media::VideoFrame::NATIVE_TEXTURE);
   if (frame_format != media::VideoFrame::NATIVE_TEXTURE)
       return VideoFrameExternalResources();
 
@@ skipping 11 matching lines @@
           VideoFrameExternalResources::STREAM_TEXTURE_RESOURCE;
       break;
     case GL_TEXTURE_RECTANGLE_ARB:
       external_resources.type = VideoFrameExternalResources::IO_SURFACE;
       break;
     default:
       NOTREACHED();
       return VideoFrameExternalResources();
   }
 
+  // Don't share the mailbox of the video frame with the compositor, because

[danakj, 2014/03/06 19:31:31]

What does this comment mean?

[dshwang, 2014/03/06 19:51:37]

Sorry for broken explanation.
ResourceProvider actually keeps this copied mailbox, instead of referencing to
video_frame->mailbox_holder(). So ubercompositor can read/write
mailbox_holder->sync_point safely.

+  // the mailbox of the video frame can be read by another thread. i.e. webgl
   external_resources.mailboxes.push_back(
       TextureMailbox(mailbox_holder->mailbox,
                      mailbox_holder->texture_target,
                      mailbox_holder->sync_point));
   external_resources.release_callbacks.push_back(
       base::Bind(&ReturnTexture, video_frame));
   return external_resources;
 }
 
 // static
@@ skipping 27 matching lines @@
   }
 
   PlaneResource recycled_resource(data.resource_id,
                                   data.resource_size,
                                   data.resource_format,
                                   data.mailbox);
   updater->recycled_resources_.push_back(recycled_resource);
 }
 
 }  // namespace cc