media::FFmpegVideoDecoder: remove ctor param |task_runner| and use a ThreadChecker instead.

content/renderer/pepper/video_decoder_shim.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 "content/renderer/pepper/video_decoder_shim.h"
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
 #include <GLES2/gl2extchromium.h>
 
@@ skipping 679 matching lines @@
 #if !defined(MEDIA_DISABLE_LIBVPX)
   if (config.codec() == media::kCodecVP9) {
     decoder_.reset(
         new media::VpxVideoDecoder(base::ThreadTaskRunnerHandle::Get()));
   } else
 #endif
 
 #if !defined(MEDIA_DISABLE_FFMPEG) && !defined(DISABLE_FFMPEG_VIDEO_DECODERS)
   {
     scoped_ptr<media::FFmpegVideoDecoder> ffmpeg_video_decoder(
-        new media::FFmpegVideoDecoder(base::ThreadTaskRunnerHandle::Get()));
+        new media::FFmpegVideoDecoder());
     ffmpeg_video_decoder->set_decode_nalus(true);
     decoder_ = ffmpeg_video_decoder.Pass();
   }
 #elif defined(MEDIA_DISABLE_LIBVPX)
   OnInitDone(false);
   return;
 #endif
 
   // VpxVideoDecoder and FFmpegVideoDecoder support only one pending Decode()
   // request.
@@ skipping 406 matching lines @@
 void VideoDecoderShim::DeleteTexture(uint32_t texture_id) {
   gpu::gles2::GLES2Interface* gles2 = context_provider_->ContextGL();
   gles2->DeleteTextures(1, &texture_id);
 }
 
 void VideoDecoderShim::FlushCommandBuffer() {
   context_provider_->ContextGL()->Flush();
 }
 
 }  // namespace content