Add missing include guards in Cocoa code.

chrome/browser/ui/cocoa/bubble_view.h

 // 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.
 
+#ifndef CHROME_BROWSER_UI_COCOA_BUBBLE_VIEW_H_
+#define CHROME_BROWSER_UI_COCOA_BUBBLE_VIEW_H_
+
 #import <Cocoa/Cocoa.h>
 
 #include "base/mac/scoped_nsobject.h"
 
 // A view class that looks like a "bubble" with rounded corners and displays
 // text inside. Can be themed. To put flush against the sides of a window, the
 // corner flags can be adjusted.
 
 // Constants that define where the bubble will have a rounded corner. If
 // not set, the corner will be square.
@@ skipping 44 matching lines @@
 // The font used to display the content string.
 - (NSFont*)font;
 
 @end
 
 // APIs exposed only for testing.
 @interface BubbleView(TestingOnly)
 - (NSString*)content;
 - (unsigned long)cornerFlags;
 @end
+
+#endif  // CHROME_BROWSER_UI_COCOA_BUBBLE_VIEW_H_