No need to include all of Cocoa, just pull in Foundation.

BUG=none
TEST=none
Review URL: http://codereview.chromium.org/4986002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@66176 0039d316-1c4b-4281-b951-d872f2087c98

base/file_util_mac.mm

@@ -4,7 +4,7 @@
 
 #include "base/file_util.h"
 
-#import <Cocoa/Cocoa.h>
+#import <Foundation/Foundation.h>
 #include <copyfile.h>
 
 #include "base/basictypes.h"