[Manifest] Add metrics recording.

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.
 
@@ skipping 11581 matching lines @@
     Shortcut added to the homescreen for a page containing only the
     apple-mobile-webapp-capable meta tag.
   </description>
 </action>
 
 <action name="webapps.AddShortcut.Bookmark">
   <owner>dfalcantara@chromium.org</owner>
   <description>Shortcut added to the homescreen for a bookmark.</description>
 </action>
 
+<action name="webapps.AddShortcut.Manifest">
+  <owner>mlamouri@chromium.org</owner>
+  <description>
+    Shortcut added to the homescreen with a valid Manifest. This action will be

[Mark P, 2014/10/03 19:33:18]

for my information: can this overlap with the Bookmark action?

[mlamouri (slow - plz ping), 2014/10/07 11:11:39]

Yes, as mentioned below.

+    recorded in addition of the three actions below to keep a trend of whether

[Mark P, 2014/10/03 19:33:19]

below?

alternate suggestion:
three actions below to
->
actions such as X, Y, and Z that

[mlamouri (slow - plz ping), 2014/10/07 11:11:39]

Done.

+    the webapp also add meta tags.
+  </description>
+</action>
+
 </actions>