Download: Add metric for URL clicks in chrome://downloads.

This CL adds a metrics for click events on the URL in chrome://downloads
for Chromenav.

Bug: 957346
Change-Id: I7460f5c2268c375b32c7fbede050c194a57f3fcc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1601691Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: calamity <calamity@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Dan Beam <dbeam@chromium.org>
Reviewed-by: Min Qin <qinmin@chromium.org>
Commit-Queue: Xing Liu <xingliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658796}

chrome/browser/resources/downloads/item.html

@@ -301,7 +301,7 @@
                                        data.fileExternallyRemoved)]]</span>
         </div>
 
-        <a id="url" target="_blank" focus-row-control
+        <a id="url" target="_blank" on-click="onUrlTap_" focus-row-control
             focus-type="url">[[chopUrl_(data.url)]]</a>
 
         <div id="description">[[computeDescription_(

chrome/browser/resources/downloads/item.js

@@ -441,6 +441,12 @@ cr.define('downloads', function() {
       this.mojoHandler_.openFileRequiringGesture(this.data.id);
     },
 
+    /** @private */
+    onUrlTap_: function() {
+      chrome.send('metricsHandler:recordAction',
+        ['Downloads_OpenUrlOfDownloadedItem']);
+    },
+
     /** @private */
     onPauseOrResumeTap_: function() {
       if (this.isInProgress_) {

tools/metrics/actions/actions.xml

@@ -5346,6 +5346,13 @@ should be able to be added at any place in this file.
   </description>
 </action>
 
+<action name="Downloads_OpenUrlOfDownloadedItem">
+  <owner>xingliu@chromium.org</owner>
+  <description>
+    Records clicks on the URL of download items in chrome://downloads page.
+  </description>
+</action>
+
 <action name="Duplicate">
   <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
   <description>Please enter the description of this user action.</description>