Remove all of WebCore/platform/mac which is not mentioned in WebCore.gypi.

Source/WebCore/platform/mac/WebCoreNSStringExtras.h

-/*
- * Copyright (C) 2005, 2007 Apple Computer, Inc.  All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1.  Redistributions of source code must retain the above copyright
- *     notice, this list of conditions and the following disclaimer. 
- * 2.  Redistributions in binary form must reproduce the above copyright
- *     notice, this list of conditions and the following disclaimer in the
- *     documentation and/or other materials provided with the distribution. 
- * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
- *     its contributors may be used to endorse or promote products derived
- *     from this software without specific prior written permission. 
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <objc/objc.h>
-
-#ifdef __OBJC__
-#include <Foundation/Foundation.h>
-@class NSString;
-#else
-typedef struct NSString NSString;
-#endif
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-BOOL stringIsCaseInsensitiveEqualToString(NSString *first, NSString *second);
-BOOL hasCaseInsensitiveSuffix(NSString *, NSString *suffix);
-BOOL hasCaseInsensitivePrefix(NSString *, NSString *prefix);
-BOOL hasCaseInsensitiveSubstring(NSString *, NSString *substring);
-NSString *filenameByFixingIllegalCharacters(NSString *);
-#if !PLATFORM(IOS)
-CFStringEncoding stringEncodingForResource(Handle resource);
-#endif
-
-#ifdef __cplusplus
-}
-#endif