Append parameters to webstore URL to indicate launch source.

chrome/browser/resources/ntp4/apps_page.js

 // Copyright (c) 2011 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.
 
 cr.define('ntp4', function() {
   'use strict';
 
   var localStrings = new LocalStrings;
 
   var APP_LAUNCH = {
@@ skipping 220 matching lines @@
 
       // This hack is here so that appContents.contextMenu will be the same as
       // this.contextMenu.
       var self = this;
       this.appContents_.__defineGetter__('contextMenu', function() {
         return self.contextMenu;
       });
       this.appContents_.addEventListener('contextmenu',
                                          cr.ui.contextMenuHandler);
 
-      this.isStore_ = this.appData_.is_webstore;
-      if (this.isStore_)
+      if (this.appData_.is_webstore)
         this.createAppsPromoExtras_();
 
       this.addEventListener('mousedown', this.onMousedown_, true);
       this.addEventListener('keydown', this.onKeydown_);
       this.addEventListener('blur', this.onBlur_, true);
     },
 
     /**
      * Sets the color of the favicon dominant color bar.
      * @param {string} color The css-parsable value for the color.
@@ skipping 175 matching lines @@
       this.style.right = x + 'px';
       this.style.top = y + 'px';
     },
 
     /**
      * Invoked when an app is clicked.
      * @param {Event} e The click event.
      * @private
      */
     onClick_: function(e) {
+      var is_promo = this.appsPromoExtras_ &&
+          window.getComputedStyle(this.appsPromoExtras_).display != 'none';
+      var url = !this.appData_.is_webstore ? '' :
+          is_promo ? appendParam(this.appsPromoLink_.href,
+                                 'utm_source',
+                                 'chrome-ntp-promo') :
+                     appendParam(this.appData_.url,
+                                 'utm_source',
+                                 'chrome-ntp-icon');
+
       chrome.send('launchApp',
-                  [this.appId, APP_LAUNCH.NTP_APPS_MAXIMIZED,
+                  [this.appId, APP_LAUNCH.NTP_APPS_MAXIMIZED, url,
                    e.altKey, e.ctrlKey, e.metaKey, e.shiftKey, e.button]);
 
       // Don't allow the click to trigger a link or anything
       e.preventDefault();
     },
 
     /**
      * Invoked when the user presses a key while the app is focused.
      * @param {Event} e The key event.
      * @private
      */
     onKeydown_: function(e) {
       if (e.keyIdentifier == 'Enter') {
         chrome.send('launchApp',
-                    [this.appId, APP_LAUNCH.NTP_APPS_MAXIMIZED,
+                    [this.appId, APP_LAUNCH.NTP_APPS_MAXIMIZED, '',
                      e.altKey, e.ctrlKey, e.metaKey, e.shiftKey, 0]);
         e.preventDefault();
         e.stopPropagation();
       }
     },
 
     /**
      * Adds a node to the list of targets that will launch the app. This list
      * is also used in onMousedown to determine whether the app contents should
      * be shown as active (if we don't do this, then clicking anywhere in
@@ skipping 327 matching lines @@
     appNotificationChanged: appNotificationChanged,
     AppsPage: AppsPage,
     launchAppAfterEnable: launchAppAfterEnable,
   };
 });
 
 // TODO(estade): update the content handlers to use ntp namespace instead of
 // making these global.
 var appNotificationChanged = ntp4.appNotificationChanged;
 var launchAppAfterEnable = ntp4.launchAppAfterEnable;