Add metrics for interactions with the Apps Launcher promo dialog.

chrome/browser/ui/webui/ntp/app_launcher_handler.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_NTP_APP_LAUNCHER_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_NTP_APP_LAUNCHER_HANDLER_H_
 
 #include <set>
 #include <string>
 
@@ skipping 85 matching lines @@
   void HandleGenerateAppForLink(const base::ListValue* args);
 
   // Callback for the "recordAppLaunchByURL" message. Takes an escaped URL and a
   // launch source (integer), and if the URL represents an app, records the
   // action for UMA.
   void HandleRecordAppLaunchByUrl(const base::ListValue* args);
 
   // Callback for "stopShowingAppLauncherPromo" message.
   void StopShowingAppLauncherPromo(const base::ListValue* args);
 
+  // Callback for "onLearnMore" message.
+  void OnLearnMore(const base::ListValue* args);

[miket_OOO, 2013/06/25 15:57:25]

I know you were just following the pattern, but these comments don't tell the
reader anything, and they're subject to copy/paste errors.

[MAD, 2013/06/26 03:33:40]

Done.

+
   // Callback for "closeNotification" message.
   void HandleNotificationClose(const base::ListValue* args);
 
   // Callback for "setNotificationsDisabled" message.
   void HandleSetNotificationsDisabled(const base::ListValue* args);
 
   // Register app launcher preferences.
   static void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
   // Records the given type of app launch for UMA.
@@ skipping 98 matching lines @@
   // when the app is added to the page (via getAppsCallback or appAdded).
   std::string highlight_app_id_;
 
   // Used for favicon loading tasks.
   CancelableTaskTracker cancelable_task_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(AppLauncherHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_NTP_APP_LAUNCHER_HANDLER_H_