Add a count for Suggested Articles usage.

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 10265 matching lines @@
 <action name="NewProfileWindowByIndex">
   <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="NewTab">
   <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="NewTabPage_ContentSuggestions_ArticlesUsageCount">
+  <owner>markusheintz@chromium.org</owner>
+  <description>
+    Records when a user uses the &quot;Articles for you&quot; section on the New
+    Tab Page. Usage is defined by scrolling to the section and opening an

[Marc Treib, 2016/11/17 11:10:23]

nit: s/and/or/
(as it is, IMO it sounds like it'd only be recorded after both events have
happened, but in fact it's recorded for the scroll and then again for the click)

[markusheintz_, 2016/11/17 13:48:47]

I change the description PTAL

+    article suggestion.
+  </description>
+</action>
+
 <action name="NewTabPage_ReopenTab">
   <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="NewTab_Button">
   <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 5607 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>