fixed the distorted behavior on the mediastreaminfobar on Mac

chrome/browser/ui/cocoa/infobars/media_stream_infobar_controller.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_COCOA_INFOBARS_MEDIA_STREAM_INFOBAR_CONTROLLER_H_
 #define CHROME_BROWSER_UI_COCOA_INFOBARS_MEDIA_STREAM_INFOBAR_CONTROLLER_H_
 
 #import "chrome/browser/ui/cocoa/infobars/infobar_controller.h"
 
 #import "base/memory/scoped_nsobject.h"
 #include "base/memory/scoped_ptr.h"
 
 class InfoBarTabHelper;
 class MediaStreamDevicesMenuModel;
 class MediaStreamInfoBarDelegate;
 @class NSButton;
 @class NSPopUpButton;
 @class NSTextField;
 
 // The class handles the Mac OS X specifics for the MediaStream infobar allowing
 // or denying capture device usage.
 @interface MediaStreamInfoBarController : InfoBarController {
  @protected
   // Contains all text displayed on the infobar.
   scoped_nsobject<NSTextField> label1_;
   // Contains a list of video and audio capture devices.
   scoped_nsobject<NSPopUpButton> deviceMenu_;
   // Menu model for MediaStream capture devices.
   scoped_ptr<MediaStreamDevicesMenuModel> deviceMenuModel_;
+  // Space between controls in pixels - generated from the NIB.
+  CGFloat spaceBetweenControls_;
 }
 
 - (id)initWithDelegate:(MediaStreamInfoBarDelegate*)delegate
                  owner:(InfoBarTabHelper*)owner;
 
 // Called when the selection in the device menu has changed.
 - (IBAction)deviceMenuChanged:(id)sender;
 
 @end
 
 #endif  // CHROME_BROWSER_UI_COCOA_INFOBARS_MEDIA_STREAM_INFOBAR_CONTROLLER_H_