[Video] Only start tracking foreground time if the video was resumed.

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 7e09c634a5b91237002cc0b48641adb9ddfa891a..cdbeb31953970b44442f26328099767dfdb70627 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -26205,6 +26205,11 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="Media.Video.TimeFromForegroundToFirstFrame" units="ms">
+  <obsolete>
+    Deprecated as of 01/18/2017 in issue 670150. Replaced by
+    Media.Video.TimeFromForegroundToFirstFrame.DisabledTrack and
+    Media.Video.TimeFromForegroundToFirstFrame.Paused.
+  </obsolete>
   <owner>avayvod@chromium.org</owner>
   <owner>dalecurtis@chromium.org</owner>
   <summary>
@@ -26213,6 +26218,30 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Media.Video.TimeFromForegroundToFirstFrame.DisabledTrack"
+    units="ms">
+  <owner>avayvod@chromium.org</owner>
+  <owner>dalecurtis@chromium.org</owner>
+  <summary>
+    Records the time between the moment when the video element that had video
+    track disabled in the background is brought to the foreground and when the
+    video frame compositor outputs the next frame. Recorded even if disabling
+    video track in the background is turned off to collect data for the control
+    group.
+  </summary>
+</histogram>
+
+<histogram name="Media.Video.TimeFromForegroundToFirstFrame.Paused" units="ms">
+  <owner>avayvod@chromium.org</owner>
+  <owner>dalecurtis@chromium.org</owner>
+  <summary>
+    Records the time between the moment when the video element that was paused
+    in the background is brought to the foreground and when the video frame
+    compositor outputs the next frame. Recorded even if disabling pausing video
+    in the background is turned off to collect data for the control group.
+  </summary>
+</histogram>
+
 <histogram name="Media.VideoCapture.AspectRatio" units="%">
   <owner>mcasas@chromium.org</owner>
   <summary>