app_list: Make contact results use the RTC extension API.

chrome/browser/extensions/api/rtc_private/rtc_private_api.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_EXTENSIONS_API_RTC_PRIVATE_RTC_PRIVATE_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_RTC_PRIVATE_RTC_PRIVATE_API_H_
 
 class Profile;
 
 namespace contacts {
 class Contact;
@@ skipping 11 matching lines @@
     LAUNCH_VIDEO,
     LAUNCH_VOICE,
   };
 
   // Raises chrome.rtcPrivate.onLaunch event which is used to launch the default
   // RTC application in ChromeOS. |action| defines the context of the launch
   // event. Optional |contact| information is passed as event payload if launch
   // event is related to a particilar contact.
   static void DispatchLaunchEvent(Profile* profile,
                                   LaunchAction action,
-                                  contacts::Contact* contact);
+                                  const contacts::Contact* contact);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_RTC_PRIVATE_RTC_PRIVATE_API_H_