cc: Send BeginFrame to VideoFrameController when added if we're inside a frame.

cc/layers/video_frame_provider_client_impl.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/layers/video_frame_provider_client_impl.h"
 
 #include "base/trace_event/trace_event.h"
 #include "cc/base/math_util.h"
 #include "cc/layers/video_layer_impl.h"
 #include "media/base/video_frame.h"
@@ skipping 100 matching lines @@
   provider_ = nullptr;
   if (rendering_)
     StopRendering();
 }
 
 void VideoFrameProviderClientImpl::StartRendering() {
   DCHECK(thread_checker_.CalledOnValidThread());
   TRACE_EVENT0("cc", "VideoFrameProviderClientImpl::StartRendering");
   DCHECK(!rendering_);
   DCHECK(!stopped_);
+  rendering_ = true;
   client_->AddVideoFrameController(this);
-  rendering_ = true;
 }
 
 void VideoFrameProviderClientImpl::StopRendering() {
   DCHECK(thread_checker_.CalledOnValidThread());
   TRACE_EVENT0("cc", "VideoFrameProviderClientImpl::StopRendering");
   DCHECK(rendering_);
   DCHECK(!stopped_);
   client_->RemoveVideoFrameController(this);
   rendering_ = false;
 }
@@ skipping 32 matching lines @@
   if (!provider_ ||
       !provider_->UpdateCurrentFrame(args.frame_time + args.interval,
                                      args.frame_time + 2 * args.interval)) {
     return;
   }
 
   DidReceiveFrame();
 }
 
 }  // namespace cc