Add UMA metrics for ffmpeg color ranges.

media/ffmpeg/ffmpeg_common.cc

Index: media/ffmpeg/ffmpeg_common.cc
diff --git a/media/ffmpeg/ffmpeg_common.cc b/media/ffmpeg/ffmpeg_common.cc
index 72b31252f8508df48cc10c7d2d832264525233cd..e60674ef2a8323142d738aa37e742274aab3a2d6 100644
--- a/media/ffmpeg/ffmpeg_common.cc
+++ b/media/ffmpeg/ffmpeg_common.cc
@@ -6,6 +6,7 @@
 
 #include "base/basictypes.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/video_frame.h"
 #include "media/base/video_util.h"
@@ -369,6 +370,14 @@ void AVStreamToVideoDecoderConfig(
   gfx::Size natural_size = GetNaturalSize(
       visible_rect.size(), aspect_ratio.num, aspect_ratio.den);
 
+  if (record_stats) {
+    UMA_HISTOGRAM_ENUMERATION(
+        "Media.VideoPixelFormat", stream->codec->pix_fmt, PIX_FMT_NB + 1);

[scherkus (not reviewing), 2013/10/28 21:16:39]

you're correct that since these values aren't guaranteed to be stable, we
shouldn't use them for UMA

let's use VideoFrame::Format and add a comment to that enum that values
shouldn't change, similar to other enums:
https://code.google.com/p/chromium/codesearch#chromium/src/media/base/pipelin...

+    UMA_HISTOGRAM_ENUMERATION("Media.VideoColorRange",
+                              stream->codec->color_range,
+                              AVCOL_RANGE_NB + 1);
+  }
+
   VideoFrame::Format format = PixelFormatToVideoFormat(stream->codec->pix_fmt);
   if (codec == kCodecVP9) {
     // TODO(tomfinegan): libavcodec doesn't know about VP9.