Add metrics for Webstore Gallery Widget app

components/chrome_apps/webstore_widget/app/main.js

 // 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.
 
 //<include src="../../../../ui/webui/resources/js/cr.js">
 //<include src="../../../../ui/webui/resources/js/load_time_data.js">
 //<include src="../../../../ui/webui/resources/js/i18n_template_no_process.js">
 //<include src="../../../../ui/webui/resources/js/cr/event_target.js">
 //<include src="../../../../ui/webui/resources/js/cr/ui/dialogs.js">
 
@@ skipping 50 matching lines @@
     strings: {
       UI_LOCALE: getString('language'),
       LINK_TO_WEBSTORE: getString('LINK_TO_WEBSTORE'),
       INSTALLATION_FAILED_MESSAGE: getString('INSTALLATION_FAILED_MESSAGE'),
       LOADING_SPINNER_ALT: getString('LOADING_SPINNER_ALT'),
       INSTALLING_SPINNER_ALT: getString('INSTALLING_SPINNER_ALT')
     },
 
     metricsImpl: {
       /**
+       * Map from interval name to interval start timestamp.
+       * @type {Object<string, Date>}
+       */
+      intervals: {},
+
+      /**
        * @param {string} enumName
        * @param {number} value
        * @param {number} enumSize
        */
-      recordEnum: function(enumName, value, enumSize) {},
+      recordEnum: function(enumName, value, enumSize) {
+        var index = (value >= 0 && value < enumSize) ? value : enumSize;
+        chrome.metricsPrivate.recordValue({
+          'metricName': 'WebstoreWidgetApp.' + enumName,
+          'type': 'histogram-linear',
+          'min': 1,
+          'max': enumSize,
+          'buckets': enumSize + 1
+        }, index);
+      },
 
       /** @param {string} actionName */
-      recordUserAction: function(actionName) {},
+      recordUserAction: function(actionName) {
+        chrome.metricsPrivate.recordUserAction(
+            'WebstoreWidgetApp.' + actionName);
+      },
 
       /** @param {string} intervalName */
-      startInterval: function(intervalName) {},
+      startInterval: function(intervalName) {
+        this.intervals[intervalName] = Date.now();
+      },
 
       /** @param {string} intervalName */
-      recordInterval: function(intervalName) {}
+      recordInterval: function(intervalName) {
+        if (!intervalName in this.intervals) {
+          console.error('Interval \'' + intervalName + '\' not started');
+          return;
+        }
+
+       chrome.metricsPrivate.recordTime(
+           'WebstoreWidgetApp.' + intervalName,
+           Date.now() - this.intervals[intervalName]);
+        delete this.intervals[intervalName];
+      }
     },
 
     /**
      * @param {string} itemId Item to be installed.
      * @param {function(?string)} callback Callback param is the error message,
      *     which is set to null on success.
      */
     installWebstoreItem: function(itemId, callback) {
       chrome.webstoreWidgetPrivate.installWebstoreItem(
           itemId,
@@ skipping 110 matching lines @@
           var result = widgetContainer.finalizeAndGetResult();
           showWidgetResult(result.result);
         })
         /** @param {*} error */
         .catch(function(error) {
           showWidgetResult(CWSWidgetContainer.Result.FAILED);
         });
   });
 });
 })();