Replace WaitableEvents and ConditionalVariables in VideoRendererBase tests with MessageLoop.

media/filters/decrypting_audio_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 <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/message_loop.h"
 #include "media/base/buffers.h"
 #include "media/base/data_buffer.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/decrypt_config.h"
 #include "media/base/gmock_callback_support.h"
-#include "media/base/mock_callback.h"
 #include "media/base/mock_filters.h"
+#include "media/base/test_helpers.h"
 #include "media/filters/decrypting_audio_decoder.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 using ::testing::_;
 using ::testing::AtMost;
 using ::testing::IsNull;
 using ::testing::ReturnRef;
 using ::testing::SaveArg;
 using ::testing::StrictMock;
 
@@ skipping 438 matching lines @@
   EXPECT_CALL(*demuxer_, Read(_))
       .WillOnce(RunCallback<0>(DemuxerStream::kConfigChanged,
                                scoped_refptr<DecoderBuffer>()));
 
   // TODO(xhwang): Update this test when kConfigChanged is supported in
   // DecryptingAudioDecoder.
   ReadAndExpectFrameReadyWith(AudioDecoder::kDecodeError, NULL);
 }
 
 }  // namespace media