Allow media track switching.

media/renderers/default_renderer_factory.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/renderers/default_renderer_factory.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
@@ skipping 86 matching lines @@
 std::unique_ptr<Renderer> DefaultRendererFactory::CreateRenderer(
     const scoped_refptr<base::SingleThreadTaskRunner>& media_task_runner,
     const scoped_refptr<base::TaskRunner>& worker_task_runner,
     AudioRendererSink* audio_renderer_sink,
     VideoRendererSink* video_renderer_sink,
     const RequestSurfaceCB& request_surface_cb) {
   DCHECK(audio_renderer_sink);
 
   std::unique_ptr<AudioRenderer> audio_renderer(new AudioRendererImpl(
       media_task_runner, audio_renderer_sink,
-      CreateAudioDecoders(media_task_runner), media_log_));
+      // Unretained is safe here, because the RendererFactory is guaranteed to
+      // outlive the RendererImpl. The RendererImpl is destroyed when WMPI
+      // destructor calls pipeline_controller_.Stop() -> PipelineImpl::Stop() ->
+      // RendererWrapper::Stop -> RendererWrapper::DestroyRenderer(). And the
+      // RendererFactory is owned by WMPI and gets called after WMPI destructor
+      // finishes.
+      base::Bind(&DefaultRendererFactory::CreateAudioDecoders,
+                 base::Unretained(this), media_task_runner),
+      media_log_));
 
   GpuVideoAcceleratorFactories* gpu_factories = nullptr;
   if (!get_gpu_factories_cb_.is_null())
     gpu_factories = get_gpu_factories_cb_.Run();
 
   std::unique_ptr<VideoRenderer> video_renderer(new VideoRendererImpl(
       media_task_runner, worker_task_runner, video_renderer_sink,
-      CreateVideoDecoders(media_task_runner, request_surface_cb, gpu_factories),
+      // Unretained is safe here, because the RendererFactory is guaranteed to
+      // outlive the RendererImpl. The RendererImpl is destroyed when WMPI
+      // destructor calls pipeline_controller_.Stop() -> PipelineImpl::Stop() ->
+      // RendererWrapper::Stop -> RendererWrapper::DestroyRenderer(). And the
+      // RendererFactory is owned by WMPI and gets called after WMPI destructor
+      // finishes.
+      base::Bind(&DefaultRendererFactory::CreateVideoDecoders,
+                 base::Unretained(this), media_task_runner, request_surface_cb,
+                 gpu_factories),
       true, gpu_factories, media_log_));
 
   return base::MakeUnique<RendererImpl>(
       media_task_runner, std::move(audio_renderer), std::move(video_renderer));
 }
 
 }  // namespace media