[ObjC ARC] Converts ios/chrome/browser/ui/tabs:tabs to ARC.

ios/chrome/browser/ui/tabs/tab_strip_view.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_BROWSER_UI_TABS_TAB_STRIP_VIEW_H_
 #define IOS_CHROME_BROWSER_UI_TABS_TAB_STRIP_VIEW_H_
 
 #import <UIKit/UIKit.h>
 
 // Notification sent by the tab strip when its frame changes.
@@ skipping 10 matching lines @@
 // TabStripView does not perform any other subview layout.
 - (void)layoutTabStripSubviews;
 // Called from UIView |-traitCollectionDidChange:|.
 - (void)traitCollectionDidChange:(UITraitCollection*)previousTraitCollection;
 @end
 
 // View class for the tabstrip.  Contains one TabView per open tab and manages
 // tab overflow behavior.
 @interface TabStripView : UIScrollView {
  @private
-  id<TabStripViewLayoutDelegate> layoutDelegate_;
+  id<TabStripViewLayoutDelegate> __weak layoutDelegate_;
 }
 
-@property(nonatomic, readwrite, assign) id<TabStripViewLayoutDelegate>
+@property(nonatomic, readwrite, weak) id<TabStripViewLayoutDelegate>
     layoutDelegate;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_TABS_TAB_STRIP_VIEW_H_