[Downloads] Remove externally deleted items from downloads history

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 903 matching lines @@
   </description>
 </action>
 
 <action name="AlertIndicatorButton_Unmute">
   <owner>miu@chromium.org</owner>
   <description>
     User clicked the tab alert indicator button to unmute the tab.
   </description>
 </action>
 
+<action name="Android.DownloadManager.CheckForExternallyRemovedItems">
+  <owner>dfalcantara@chromium.org</owner>
+  <owner>twellington@chromium.org</owner>
+  <owner>ianwen@chromium.org</owner>
+  <description>
+    A request was issued to check the file system for download items that were
+    externally deleted e.g. through a third-party download manager.
+  </description>
+</action>
+
 <action name="Android.DownloadManager.Delete">
   <owner>dfalcantara@chromium.org</owner>
   <owner>twellington@chromium.org</owner>
   <owner>ianwen@chromium.org</owner>
   <description>User deleted one or more download items.</description>
 </action>
 
+<action name="Android.DownloadManager.Item.ExternallyDeleted">
+  <owner>dfalcantara@chromium.org</owner>
+  <owner>twellington@chromium.org</owner>
+  <owner>ianwen@chromium.org</owner>
+  <description>
+    A download tracked by the Chrome download service was externally deleted
+    e.g. through a third-party download manager.
+  </description>
+</action>
+
 <action name="Android.DownloadManager.OpenDrawer">
   <owner>dfalcantara@chromium.org</owner>
   <owner>twellington@chromium.org</owner>
   <owner>ianwen@chromium.org</owner>
   <description>
     User opened the navigation drawer in Chrome's download manager.
   </description>
 </action>
 
-<action name="Android.DownloadManager.Share.Deleted">
+<action name="Android.DownloadManager.SelectionEstablished">
   <owner>dfalcantara@chromium.org</owner>
   <owner>twellington@chromium.org</owner>
   <owner>ianwen@chromium.org</owner>
   <description>
-    User tapped on the share button with only externally deleted download items
-    selected.
+    User established a long-press selection in Chrome's download manager.
   </description>
 </action>
 
 <action name="Android.LauncherShortcut.NewIncognitoTab">
   <owner>twellington@chromium.org</owner>
   <description>
     User tapped on the 'New Incognito Tab' launcher shortcut option.
   </description>
 </action>
 
@@ skipping 14610 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>