Remove single bookmark widget.

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 immediatly after a user takes the
@@ skipping 1835 matching lines @@
     navigable hierarchy of the user's bookmarks, to their homescreen on Android.
   </description>
 </action>
 
 <action name="BookmarkShortcutWidgetAdded">
   <owner>aurimas@chromium.org</owner>
   <description>
     User added the &quot;bookmark shortcut&quot; widget, which is an icon to
     open a single bookmark in Chrome, to their homescreen on Android.
   </description>
+  <obsolete>
+    Deprecated as of 10/2015. The widget was removed from Chrome.
+  </obsolete>
 </action>
 
 <action name="Bookmarks_Search">
   <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="BrowserForSystemProfile">
   <owner>mlerman@chromium.org</owner>
   <description>
@@ skipping 11189 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>