Report user actions when gesture starts and stops in user_model.

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 11712 matching lines @@
 <action name="ReloadIgnoringCache">
   <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="RemoveFormat">
   <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="RendererScheduler.UserModel.GestureEnd">
+  <owner>beaudoin@chromium.org</owner>
+  <description>
+    Fired whenever a gesture ends (touch, scroll, pinch, fling) and the renderer
+    scheduler is made aware of it.

[Ilya Sherman, 2016/03/21 08:09:44]

Are you sure you don't want to break this metric down by the specific gesture?

[beaudoin, 2016/03/23 02:46:42]

They are all considered similar for the current purpose, not breaking it down
for now.

+  </description>
+</action>
+
+<action name="RendererScheduler.UserModel.GestureStart">
+  <owner>beaudoin@chromium.org</owner>
+  <description>
+    Fired whenever a gesture starts (touch, scroll, pinch, fling) and the
+    renderer scheduler is made aware of it.
+  </description>
+</action>
+
 <action name="ReportBug">
   <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="ResetProfile">
   <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 2300 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>