Avoid unnecessary post task during frame delivery.

media/filters/vpx_video_decoder.cc

 // 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.
 
 #include "media/filters/vpx_video_decoder.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 373 matching lines @@
   InitCB bound_init_cb = BindToCurrentLoop(init_cb);
 
   if (config.is_encrypted() || !ConfigureDecoder(config)) {
     bound_init_cb.Run(false);
     return;
   }
 
   // Success!
   config_ = config;
   state_ = kNormal;
-  output_cb_ = BindToCurrentLoop(output_cb);
+  output_cb_ = offload_task_runner_ ? BindToCurrentLoop(output_cb) : output_cb;
   bound_init_cb.Run(true);
 }
 
 void VpxVideoDecoder::DecodeBuffer(const scoped_refptr<DecoderBuffer>& buffer,
                                    const DecodeCB& bound_decode_cb) {
   DCHECK_NE(state_, kUninitialized)
       << "Called Decode() before successful Initialize()";
 
   if (state_ == kError) {
     bound_decode_cb.Run(DecodeStatus::DECODE_ERROR);
@@ skipping 320 matching lines @@
       (*video_frame)->visible_data(VideoFrame::kUPlane),
       (*video_frame)->stride(VideoFrame::kUPlane),
       (*video_frame)->visible_data(VideoFrame::kVPlane),
       (*video_frame)->stride(VideoFrame::kVPlane), coded_size.width(),
       coded_size.height());
 
   return true;
 }
 
 }  // namespace media