Add UMA reporting for RTCVideoDecoder.

content/renderer/media/rtc_video_decoder.cc

Index: content/renderer/media/rtc_video_decoder.cc
diff --git a/content/renderer/media/rtc_video_decoder.cc b/content/renderer/media/rtc_video_decoder.cc
index adce1f61b7e6dcb84bba726ce4050a797da031d0..5e4721a43459ecf92dd906ad1d0e930e1647f00e 100644
--- a/content/renderer/media/rtc_video_decoder.cc
+++ b/content/renderer/media/rtc_video_decoder.cc
@@ -8,6 +8,7 @@
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "base/metrics/histogram.h"
 #include "base/safe_numerics.h"
 #include "base/stl_util.h"
 #include "base/task_runner_util.h"
@@ -171,6 +172,7 @@ int32_t RTCVideoDecoder::InitDecode(const webrtc::VideoCodec* codecSettings,
                                          kMaxInFlightDecodes,
                                          kSharedMemorySegmentBytes));
   }
+  UMA_HISTOGRAM_BOOLEAN("Media.RTCVideoDecoderInitDecode", true);

[Ami GONE FROM CHROMIUM, 2013/09/11 17:27:35]

Do you want also want a false log somewhere to indicate attempt+failure for HW
decode?

[Ami GONE FROM CHROMIUM, 2013/09/11 17:27:35]

You'll also need to edit histograms.xml if you want to see this on the UMA
dashboard.

[wuchengli, 2013/09/13 07:38:23]

Done.

[wuchengli, 2013/09/13 07:38:23]

Done. I didn't use enumeration for InitDecode because success/fail is enough.

I also added Media.RTCVideoDecoderError for errors from VDA.

   return WEBRTC_VIDEO_CODEC_OK;
 }