Replace WaitableEvents and ConditionalVariables in VideoRendererBase tests with MessageLoop.

content/renderer/media/rtc_video_decoder_unittest.cc

 // Copyright (c) 2012 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/media/rtc_video_decoder.h"
 
 #include <deque>
 
 #include "base/bind.h"
 #include "base/memory/singleton.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
 #include "media/base/data_buffer.h"
 #include "media/base/limits.h"
-#include "media/base/mock_callback.h"
 #include "media/base/mock_filters.h"
+#include "media/base/test_helpers.h"
 #include "media/base/video_frame.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/libjingle/source/talk/media/base/videoframe.h"
 
 using ::testing::_;
 using ::testing::AnyNumber;
 using ::testing::DoAll;
 using ::testing::Message;
 using ::testing::Return;
 using ::testing::ReturnNull;
@@ skipping 304 matching lines @@
   Stop();
 
   // Any read after stopping should be immediately satisfied.
   EXPECT_CALL(*this, FrameReady(media::VideoDecoder::kOk,
                                 scoped_refptr<media::VideoFrame>()));
   decoder_->Read(read_cb_);
   message_loop_.RunUntilIdle();
 }
 
 }  // namespace content