Add methods for telling V8 how much memory audio/video is using.

media/renderers/video_renderer_impl_unittest.cc

Index: media/renderers/video_renderer_impl_unittest.cc
diff --git a/media/renderers/video_renderer_impl_unittest.cc b/media/renderers/video_renderer_impl_unittest.cc
index fdac65ba4ed6b4fed71cbbfbb074e455183fa2f2..f7dcb10d6ce8855a8a3a16899b7ec5f9675128e8 100644
--- a/media/renderers/video_renderer_impl_unittest.cc
+++ b/media/renderers/video_renderer_impl_unittest.cc
@@ -677,6 +677,7 @@ TEST_F(VideoRendererImplTest, RenderingStartedThenStopped) {
     event.RunAndWait();
     Mock::VerifyAndClearExpectations(&mock_cb_);
     EXPECT_EQ(0u, last_pipeline_statistics_.video_frames_dropped);
+    EXPECT_EQ(460800, last_pipeline_statistics_.video_memory_usage);
   }
 
   // Consider the case that rendering is faster than we setup the test event.
@@ -704,6 +705,7 @@ TEST_F(VideoRendererImplTest, RenderingStartedThenStopped) {
   // reported
   EXPECT_EQ(0u, last_pipeline_statistics_.video_frames_dropped);
   EXPECT_EQ(4u, last_pipeline_statistics_.video_frames_decoded);
+  EXPECT_EQ(460800, last_pipeline_statistics_.video_memory_usage);
 
   AdvanceTimeInMs(30);
   WaitForEnded();