Fix crash in renderer initialization when media pipeline is stopped

media/renderers/renderer_impl.cc

Index: media/renderers/renderer_impl.cc
diff --git a/media/renderers/renderer_impl.cc b/media/renderers/renderer_impl.cc
index 87212d8214423f6ed38b7cd4344feca1ae16476e..7e20243fb209c5f7934f121127ad558d99ad7e49 100644
--- a/media/renderers/renderer_impl.cc
+++ b/media/renderers/renderer_impl.cc
@@ -384,7 +384,9 @@ void RendererImpl::InitializeAudioRenderer() {
   PipelineStatusCB done_cb =
       base::Bind(&RendererImpl::OnAudioRendererInitializeDone, weak_this_);
 
-  if (!demuxer_stream_provider_->GetStream(DemuxerStream::AUDIO)) {
+  DemuxerStream* audio_stream =
+      demuxer_stream_provider_->GetStream(DemuxerStream::AUDIO);
+  if (!audio_stream) {
     audio_renderer_.reset();
     task_runner_->PostTask(FROM_HERE, base::Bind(done_cb, PIPELINE_OK));
     return;
@@ -394,9 +396,8 @@ void RendererImpl::InitializeAudioRenderer() {
       new RendererClientInternal(DemuxerStream::AUDIO, this));
   // Note: After the initialization of a renderer, error events from it may
   // happen at any time and all future calls must guard against STATE_ERROR.
-  audio_renderer_->Initialize(
-      demuxer_stream_provider_->GetStream(DemuxerStream::AUDIO), cdm_context_,
-      audio_renderer_client_.get(), done_cb);
+  audio_renderer_->Initialize(audio_stream, cdm_context_,
+                              audio_renderer_client_.get(), done_cb);
 }
 
 void RendererImpl::OnAudioRendererInitializeDone(PipelineStatus status) {
@@ -429,7 +430,9 @@ void RendererImpl::InitializeVideoRenderer() {
   PipelineStatusCB done_cb =
       base::Bind(&RendererImpl::OnVideoRendererInitializeDone, weak_this_);
 
-  if (!demuxer_stream_provider_->GetStream(DemuxerStream::VIDEO)) {
+  DemuxerStream* video_stream =
+      demuxer_stream_provider_->GetStream(DemuxerStream::VIDEO);
+  if (!video_stream) {
     video_renderer_.reset();
     task_runner_->PostTask(FROM_HERE, base::Bind(done_cb, PIPELINE_OK));
     return;
@@ -438,8 +441,7 @@ void RendererImpl::InitializeVideoRenderer() {
   video_renderer_client_.reset(
       new RendererClientInternal(DemuxerStream::VIDEO, this));
   video_renderer_->Initialize(
-      demuxer_stream_provider_->GetStream(DemuxerStream::VIDEO), cdm_context_,
-      video_renderer_client_.get(),
+      video_stream, cdm_context_, video_renderer_client_.get(),
       base::Bind(&RendererImpl::GetWallClockTimes, base::Unretained(this)),
       done_cb);
 }