[Video] Record the results of background video optimization checks.

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 7e5b2162dc2b7af8ef1ed9414c85ea91828d46b4..43aed6db996edb309e7b68ddc654a05a7f01c5cd 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -28162,6 +28162,26 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Media.Video.ShouldDisableVideoWhenHiddenResult"
+    enum="MediaBackgroundOptimizationCandidacyResult">
+  <owner>avayvod@chromium.org</owner>
+  <owner>media-dev@chromium.org</owner>
+  <summary>
+    The reason behind the video track of a media element being disabled or not
+    when the tab containing the element is hidden.
+  </summary>
+</histogram>
+
+<histogram name="Media.Video.ShouldPauseVideoWhenHiddenResult"
+    enum="MediaBackgroundOptimizationCandidacyResult">
+  <owner>avayvod@chromium.org</owner>
+  <owner>media-dev@chromium.org</owner>
+  <summary>
+    The reason behind the video element being paused or not when the tab
+    containing it is hidden.
+  </summary>
+</histogram>
+
 <histogram name="Media.Video.TimeFromForegroundToFirstFrame" units="ms">
   <obsolete>
     Deprecated as of 01/18/2017 in issue 670150. Replaced by
@@ -103276,6 +103296,15 @@ from previous Chrome versions.
   <int value="3" label="Low and High confidence."/>
 </enum>
 
+<enum name="MediaBackgroundOptimizationCandidacyResult" type="int">
+  <int value="0" label="SuccessForDuration"/>
+  <int value="1" label="SuccessForKeyframeDistance"/>
+  <int value="2" label="SuccessForVideoOnly"/>
+  <int value="3" label="FailForKeyframeDistance"/>
+  <int value="4" label="FailForRemote"/>
+  <int value="5" label="FailForStreaming"/>
+</enum>
+
 <enum name="MediaCommand" type="int">
   <int value="0" label="Resume"/>
   <int value="1" label="Pause"/>