Remove remaining calls to deprecated MessageLoop methods on Mac.

media/audio/mac/audio_low_latency_input_mac_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 <stdint.h>
 
 #include <memory>
 
 #include "base/environment.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "base/test/test_timeouts.h"
 #include "base/threading/platform_thread.h"
 #include "media/audio/audio_device_description.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_manager_base.h"
 #include "media/audio/audio_unittest_util.h"
 #include "media/audio/mac/audio_low_latency_input_mac.h"
 #include "media/base/seekable_buffer.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using ::testing::_;
 using ::testing::AnyNumber;
 using ::testing::AtLeast;
 using ::testing::Ge;
 using ::testing::NotNull;
 
 namespace media {
 
 ACTION_P4(CheckCountAndPostQuitTask, count, limit, loop, closure) {
   if (++*count >= limit) {
-    loop->PostTask(FROM_HERE, closure);
+    loop->task_runner()->PostTask(FROM_HERE, closure);
   }
 }
 
 class MockAudioInputCallback : public AudioInputStream::AudioInputCallback {
  public:
   MOCK_METHOD4(OnData,
                void(AudioInputStream* stream,
                     const AudioBus* src,
                     uint32_t hardware_delay_bytes,
                     double volume));
@@ skipping 235 matching lines @@
   WriteToFileAudioSink file_sink(file_name);
   fprintf(stderr, "               >> Speak into the mic while recording...\n");
   ais->Start(&file_sink);
   base::PlatformThread::Sleep(TestTimeouts::action_timeout());
   ais->Stop();
   fprintf(stderr, "               >> Recording has stopped.\n");
   ais->Close();
 }
 
 }  // namespace media