Added metrics for background video playback.

tools/metrics/actions/actions.xml

 <!--
 Copyright 2014 The Chromium Authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 -->
 
 <!--
 This file is a comprehensive list of Chrome user actions along with the owner
 and description for each user action. A user action should be tied to an actual
 action taken by a user. It should be logged immediately after a user takes the
@@ skipping 8478 matching lines @@
   </description>
 </action>
 
 <action name="Media.Controls.VolumeChangeEnd">
   <owner>mlamouri@chromium.org</owner>
   <description>
     The user stopped interacting with the control's volume slider.
   </description>
 </action>
 
+<action name="Media.Hidden">

[Ilya Sherman, 2016/08/08 22:09:10]

Is this always a user-initiated action, or can it be programmatically initiated
as well?  Please either try to write the description in the form of "The user
did X", or possibly reconsider whether you really want to record this event as a
"user action".  Mounir recently went through and marked a number of actions as
not_user_triggered because they were interfering with metrics analysis.  It
would be a shame if these metrics led to similar noise.

(Please note that this comment applies to all of the metrics, even though I am
only mentioning it here.)

[whywhat, 2016/08/11 21:51:04]

Rewrote the description. We're trying to only track user interaction here.

+  <owner>avayvod@chromium.org</owner>
+  <description>A renderer media delegate is notified it's hidden.</description>

[mlamouri (slow - plz ping), 2016/08/08 13:19:31]

I'm not sure "renderer media delegate" is the right term to use. Unless you know
the code very well it will be unclear what this means and I think we want the
description to be readable by others than the engineers who work on this code :)

[whywhat, 2016/08/11 21:51:04]

Done.

+</action>
+
+<action name="Media.RemoteControls.Pause">
+  <owner>avayvod@chromium.org</owner>
+  <description>Media delegate is requested to pause media.</description>

[mlamouri (slow - plz ping), 2016/08/08 13:19:31]

Same as above. It's very unclear what "Media delegate" or "RemoteControls" is in
this case. Even as someone who knows the code, what's the difference with this
and media session?

[whywhat, 2016/08/11 21:51:04]

Done.

+</action>
+
+<action name="Media.RemoteControls.Play">
+  <owner>avayvod@chromium.org</owner>
+  <description>Media delegate is requested to resume media.</description>
+</action>
+
+<action name="Media.Session.BackgroundResume">
+  <owner>avayvod@chromium.org</owner>
+  <description>
+    Background video playback started for the render frame.
+  </description>
+</action>
+
+<action name="Media.Session.BackgroundSuspend">
+  <owner>avayvod@chromium.org</owner>
+  <description>
+    Background video playback stopped for the render frame.
+  </description>
+</action>
+
+<action name="Media.Shown">
+  <owner>avayvod@chromium.org</owner>
+  <description>A renderer media delegate is notified it's shown.</description>
+</action>
+
 <action name="MediaContextMenu_Controls">
   <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
   <description>Please enter the description of this user action.</description>
 </action>
 
 <action name="MediaContextMenu_Loop">
   <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
   <description>Please enter the description of this user action.</description>
 </action>
 
@@ skipping 6824 matching lines @@
 <action name="webapps.AddShortcut.Manifest">
   <owner>mlamouri@chromium.org</owner>
   <description>
     Shortcut added to the homescreen with a valid Manifest. This action will be
     recorded in addition to AppShortcut, AppShortcutApple and Bookmark actions
     to keep a trend of whether the webapp also add meta tags.
   </description>
 </action>
 
 </actions>