Replace the only use of media::MockStatisticsCB with a bound method.

No need to keep useless helper mocks around. This also helps clean up
VideoRendererImpl's unit tests in preparation for switching to the
scheduler.

Review URL: https://codereview.chromium.org/566853006

Cr-Commit-Position: refs/heads/master@{#294704}

media/base/mock_filters.cc

@@ -94,8 +94,4 @@ MockDecryptor::MockDecryptor() {}
 
 MockDecryptor::~MockDecryptor() {}
 
-MockStatisticsCB::MockStatisticsCB() {}
-
-MockStatisticsCB::~MockStatisticsCB() {}
-
 }  // namespace media

media/base/mock_filters.h

@@ -240,15 +240,6 @@ class MockDecryptor : public Decryptor {
   DISALLOW_COPY_AND_ASSIGN(MockDecryptor);
 };
 
-// Helper mock statistics callback.
-class MockStatisticsCB {
- public:
-  MockStatisticsCB();
-  ~MockStatisticsCB();
-
-  MOCK_METHOD1(OnStatistics, void(const media::PipelineStatistics& statistics));
-};
-
 }  // namespace media
 
 #endif  // MEDIA_BASE_MOCK_FILTERS_H_

media/filters/video_renderer_impl_unittest.cc

@@ -65,8 +65,6 @@ class VideoRendererImplTest : public ::testing::Test {
     EXPECT_CALL(demuxer_stream_, Read(_)).WillRepeatedly(
         RunCallback<0>(DemuxerStream::kOk,
                        scoped_refptr<DecoderBuffer>(new DecoderBuffer(0))));
-    EXPECT_CALL(statistics_cb_object_, OnStatistics(_))
-        .Times(AnyNumber());
   }
 
   virtual ~VideoRendererImplTest() {}
@@ -103,8 +101,8 @@ class VideoRendererImplTest : public ::testing::Test {
         &demuxer_stream_,
         low_delay,
         status_cb,
-        base::Bind(&MockStatisticsCB::OnStatistics,
-                   base::Unretained(&statistics_cb_object_)),
+        base::Bind(&VideoRendererImplTest::OnStatisticsUpdate,
+                   base::Unretained(this)),
         base::Bind(&StrictMock<MockCB>::BufferingStateChange,
                    base::Unretained(&mock_cb_)),
         ended_event_.GetClosure(),
@@ -251,7 +249,6 @@ class VideoRendererImplTest : public ::testing::Test {
   scoped_ptr<VideoRendererImpl> renderer_;
   MockVideoDecoder* decoder_;  // Owned by |renderer_|.
   NiceMock<MockDemuxerStream> demuxer_stream_;
-  MockStatisticsCB statistics_cb_object_;
 
   // Use StrictMock<T> to catch missing/extra callbacks.
   class MockCB {
@@ -294,6 +291,8 @@ class VideoRendererImplTest : public ::testing::Test {
     message_loop_.PostTask(FROM_HERE, callback);
   }
 
+  void OnStatisticsUpdate(const PipelineStatistics& stats) {}
+
   base::MessageLoop message_loop_;
 
   // Used to protect |time_|.