Settings reset prompt: add more UI metrics.

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 14464 matching lines @@
 <action name="SettingsResetBubble.Show">
   <owner>mad@chromium.org</owner>
   <description>Please enter the description of this user action.</description>
 </action>
 
 <action name="SettingsResetPrompt_Accepted">
   <owner>alito@chromium.org</owner>
   <description>The user accepted the settings reset prompt.</description>
 </action>
 
 <action name="SettingsResetPrompt_Declined">

[csharp, 2017/04/07 18:23:28]

As discussed, probably worth deprecating this and creating a new cancelled
action (to help make the difference between declined and dismissed clearer)

[alito, 2017/04/07 19:58:58]

Done.

   <owner>alito@chromium.org</owner>
-  <description>The user declined the settings reset prompt.</description>
+  <description>
+    The user clicked the cancel button in the settings reset prompt dialog.
+  </description>
+</action>
+
+<action name="SettingsResetPrompt_Dismissed">
+  <owner>alito@chromium.org</owner>
+  <description>
+    The user dismissed the settings reset prompt, for example by clicking the x
+    in the top right corner or pressing the Escape key.
+  </description>
 </action>
 
 <action name="SettingsResetPrompt_Shown">
   <owner>alito@chromium.org</owner>
   <description>
     The settings reset dialog was displayed to the user.
   </description>
 </action>
 
 <action name="Shelf_AlignmentSetBottom">
@@ skipping 2203 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>