media: Report initial video height to UMA

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index b60418472cd77735b8f6d61532c05dfa178c0173..f298ccabc94876008a45f40159ada54e3edb1cca 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -28396,6 +28396,22 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>Pixel format used in HTML5 video. Emitted on video load.</summary>
 </histogram>
 
+<histogram name="Media.VideoHeight.Average" units="pixels">
+  <owner>xhwang@chromium.org</owner>

[DaleCurtis, 2017/04/17 19:05:59]

mlamouri@ suggested adding media-dev@chromium.org for new metrics owners. WDYT?

[xhwang, 2017/04/17 19:41:18]

SGTM!

+  <summary>
+    The height of the video frame in an HTML5 video. Reported whenever a new
+    video frame size is available (e.g. during MSE config change).
+  </summary>
+</histogram>
+
+<histogram name="Media.VideoHeight.Initial" units="pixels">
+  <owner>xhwang@chromium.org</owner>
+  <summary>
+    The height of the first video frame in an HTML5 video. Reported when the
+    first video frame is available.
+  </summary>
+</histogram>
+
 <histogram name="Media.VideoPersistence.AttemptResult"
     enum="VideoPersistenceAttemptResult">
   <owner>mlamouri@chromium.org</owner>
@@ -120337,6 +120353,15 @@ from previous Chrome versions.
   <affected-histogram name="Media.VideoCaptureManager"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="MediaVideoCategories" separator=".">
+  <suffix name="All" label="All media with a video track."/>
+  <suffix name="EME" label="EME media with a video track."/>
+  <suffix name="MSE" label="MSE media with a video track."/>
+  <suffix name="SRC" label="SRC media with a video track."/>
+  <affected-histogram name="Media.VideoHeight.Average"/>
+  <affected-histogram name="Media.VideoHeight.Initial"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="MediaWatchTimeCategories" separator=".">
   <suffix name="Audio.All"
       label="Watch time for all media with only an audio track."/>