Post GpuMemoryBufferVideoFramePool deletion on media thread

content/renderer/media/media_stream_video_renderer_sink_unittest.cc

 // Copyright 2015 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 "base/bind.h"
 #include "base/macros.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/child/child_process.h"
 #include "content/renderer/media/media_stream_video_renderer_sink.h"
@@ skipping 41 matching lines @@
         message_loop_.task_runner(), message_loop_.task_runner().get(),
         nullptr /* gpu_factories */);
 
     EXPECT_TRUE(IsInStoppedState());
   }
 
   ~MediaStreamVideoRendererSinkTest() {
     media_stream_video_renderer_sink_ = nullptr;
     registry_.reset();
     blink::WebHeap::collectAllGarbageForTesting();
+
+    // Let the message loop run to finish destroying the pool.
+    base::RunLoop().RunUntilIdle();
   }
 
   MOCK_METHOD1(RepaintCallback, void(const scoped_refptr<media::VideoFrame>&));
   MOCK_METHOD0(ErrorCallback, void(void));
 
   bool IsInStartedState() const {
     return media_stream_video_renderer_sink_->state_ ==
            MediaStreamVideoRendererSink::STARTED;
   }
   bool IsInStoppedState() const {
@@ skipping 77 matching lines @@
   ASSERT_EQ(1u, frame_ready_cbs_.size());
 
   EXPECT_CALL(*this, RepaintCallback(video_frame)).Times(1);
   frame_ready_cbs_[0].Run();
   message_loop_.RunUntilIdle();
 
   media_stream_video_renderer_sink_->Stop();
 }
 
 }  // namespace content