[Cast] VideoFrameFactory interface to vend frames with encoder affinity.

media/cast/sender/external_video_encoder.cc

 // Copyright 2014 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 "media/cast/sender/external_video_encoder.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/shared_memory.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "media/base/video_frame.h"
 #include "media/base/video_util.h"
 #include "media/cast/cast_defines.h"
 #include "media/cast/logging/logging_defines.h"
 #include "media/cast/net/cast_transport_config.h"
+#include "media/cast/sender/video_frame_factory.h"
 #include "media/video/video_encode_accelerator.h"
 
 namespace media {
 namespace cast {
 class LocalVideoEncodeAcceleratorClient;
 }  // namespace cast
 }  // namespace media
 
 namespace {
 static const size_t kOutputBufferCount = 3;
@@ skipping 451 matching lines @@
 // Inform the encoder to encode the next frame as a key frame.
 void ExternalVideoEncoder::GenerateKeyFrame() {
   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
   key_frame_requested_ = true;
 }
 
 // Inform the encoder to only reference frames older or equal to frame_id;
 void ExternalVideoEncoder::LatestFrameIdToReference(uint32 /*frame_id*/) {
   // Do nothing not supported.
 }
+
+// Allow the encoder to return a specialized video frame factory. May return
+// null, in which case a default implementation will be used instead.
+scoped_refptr<VideoFrameFactory> ExternalVideoEncoder::GetVideoFrameFactory() {
+  return nullptr;
+}
+
 }  //  namespace cast
 }  //  namespace media