mac: Remove unused includes of scoped_nsobject.h.

net/base/platform_mime_util_mac.mm

 // 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.
 
 #include "net/base/platform_mime_util.h"
 
 #import <Foundation/Foundation.h>
 
 #include <string>
 
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_cftyperef.h"
-#import "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 
 #if defined(OS_IOS)
 #include <MobileCoreServices/MobileCoreServices.h>
 #else
 #include <CoreServices/CoreServices.h>
 #endif  // defined(OS_IOS)
 
 #if !defined(OS_IOS)
 // SPI declaration; see the commentary in GetPlatformExtensionsForMimeType.
@@ skipping 73 matching lines @@
       extensions->insert(base::SysNSStringToUTF8(extension));
   } else {
     // Huh? Give up.
     base::FilePath::StringType ext;
     if (GetPreferredExtensionForMimeType(mime_type, &ext))
       extensions->insert(ext);
   }
 }
 
 }  // namespace net