Fix MSE GC, make it less aggressive, more spec-compliant

media/renderers/renderer_impl.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/renderer_impl.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "media/base/audio_renderer.h"
 #include "media/base/bind_to_current_loop.h"
+#include "media/base/buffers.h"
 #include "media/base/demuxer_stream_provider.h"
 #include "media/base/media_switches.h"
 #include "media/base/time_source.h"
 #include "media/base/video_renderer.h"
 #include "media/base/wall_clock_time_source.h"
 
 namespace media {
 
 // See |video_underflow_threshold_|.
 static const int kDefaultVideoUnderflowThresholdMs = 3000;
@@ skipping 164 matching lines @@
   DVLOG(1) << __FUNCTION__;
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   if (audio_renderer_)
     audio_renderer_->SetVolume(volume);
 }
 
 base::TimeDelta RendererImpl::GetMediaTime() {
   // No BelongsToCurrentThread() checking because this can be called from other
   // threads.
+  if (!time_source_)
+    return kNoTimestamp();
   return time_source_->CurrentMediaTime();
 }
 
 bool RendererImpl::HasAudio() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   return audio_renderer_ != NULL;
 }
 
 bool RendererImpl::HasVideo() {
   DCHECK(task_runner_->BelongsToCurrentThread());
@@ skipping 426 matching lines @@
   }
 
   // After OnError() returns, the pipeline may destroy |this|.
   base::ResetAndReturn(&error_cb_).Run(error);
 
   if (!flush_cb_.is_null())
     base::ResetAndReturn(&flush_cb_).Run();
 }
 
 }  // namespace media