[ObjC ARC] Converts ios/chrome/app:app_internal to ARC.

ios/chrome/app/main_controller.h

 // Copyright 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 IOS_CHROME_APP_MAIN_CONTROLLER_H_
 #define IOS_CHROME_APP_MAIN_CONTROLLER_H_
 
 #import <UIKit/UIKit.h>
 
 #import "ios/chrome/app/application_delegate/app_navigation.h"
@@ skipping 12 matching lines @@
 //
 // By design, it has no public API of its own. Anything interacting with
 // MainController should be doing so through a specific protocol.
 @interface MainController : NSObject<AppNavigation,
                                      BrowserLauncher,
                                      StartupInformation,
                                      TabOpening,
                                      TabSwitching>
 
 // A BrowserViewInformation object to perform BrowserViewController operations.
-@property(nonatomic, readonly) id<BrowserViewInformation>
+@property(weak, nonatomic, readonly) id<BrowserViewInformation>
     browserViewInformation;
 
 // The application window.
-@property(nonatomic, retain) UIWindow* window;
+@property(nonatomic, strong) UIWindow* window;
 
 // Contains information about the application state, for example whether the
 // safe mode is activated.
-@property(nonatomic, assign) AppState* appState;
+@property(nonatomic, weak) AppState* appState;
 
 // This metrics mediator is used to check and update the metrics accordingly to
 // to the user preferences.
-@property(nonatomic, assign) MetricsMediator* metricsMediator;
+@property(nonatomic, weak) MetricsMediator* metricsMediator;
 
 // UIResponder addition to execute a Chrome command.  Overridden in UIWindow to
 // forward the call to the application delegate. The application delegate
 // forwards the call to this class.
 - (void)chromeExecuteCommand:(id)sender;
 
 // Returns whether the tab switcher is active.
 - (BOOL)isTabSwitcherActive;
 
 @end
 
 #endif  // IOS_CHROME_APP_MAIN_CONTROLLER_H_