Add metrics for tracking how Chrome handled shortcut launches

tools/metrics/rappor/rappor.xml

 <!--
 Copyright 2015 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.
 -->
 
 <rappor-configuration>
 <!--
 This file is used to generate a comprehensive list of Chrome rappor metrics
 along with a detailed description for each histogram. See the design doc at
@@ skipping 88 matching lines @@
   </summary>
 </rappor-metric>
 
 <rappor-metric name="Extensions.PossibleAdInjection2" type="ETLD_PLUS_ONE">
   <owner>rdevlin.cronin@chromium.org</owner>
   <summary>
     The eTLD+1 of a URL that might be doing ad injection.
   </summary>
 </rappor-metric>
 
+<rappor-metric name="Launch.HomeScreen.Shortcut" type="ETLD_PLUS_ONE">
+  <owner>dfalcantara@chromium.org</owner>
+  <summary>
+    The eTLD+1 of a URL that was launched from the Android Home screen into a
+    tab.  This explicitly does not count relaunches via the Android Recents
+    menu.
+  </summary>
+</rappor-metric>
+
+<rappor-metric name="Launch.HomeScreen.Standalone" type="ETLD_PLUS_ONE">
+  <owner>dfalcantara@chromium.org</owner>
+  <summary>
+    The eTLD+1 of a URL that was launched from the Android Home screen into a
+    WebappActivity.  This explicitly does not count relaunches via the Android
+    Recents menu.
+  </summary>
+</rappor-metric>
+
 <rappor-metric name="Plugins.FlashOriginUrl" type="ETLD_PLUS_ONE">
   <owner>wfh@chromium.org</owner>
   <summary>
     The domain and registry of the top level URL of a page which attempts to
     launch a Flash NPAPI or PPAPI plugin, if the client has Flash installed
     and enabled. Recorded when the plugin frame appears for each Flash object
     found on the page, even if the plugin is click-to-play.
   </summary>
 </rappor-metric>
 
@@ skipping 84 matching lines @@
 </rappor-metric>
 
 <rappor-metric name="interstitial.ssl.domain" type="COARSE_RAPPOR_TYPE">
   <owner>nparker@chromium.org</owner>
   <summary>
     The domain+registry of a URL that triggered an SSL interstitial.     Domains
     for bad-clock warnings are not reported.
   </summary>
 </rappor-metric>
 
-<rappor-metric name="webapps.LaunchURL" type="ETLD_PLUS_ONE">
-  <owner>dfalcantara@chromium.org</owner>
-  <summary>
-    The eTLD+1 of a URL that was launched from the Android Home screen into a
-    WebappActivity.  This explicitly does not count relaunches via the Android
-    Recents menu.
-  </summary>
-</rappor-metric>
-
 </rappor-metrics>
 
 </rappor-configuration>