WebCorePrefix.h is only used for Mac OS X. Clean up dead code and remove including wtf/Platform.h.

Source/bindings/bindings.gyp

 #
 # Copyright (C) 2013 Google 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:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 52 matching lines @@
       'include_dirs': [
         # FIXME:  Remove <(SHARED_INTERMEDIATE_DIR)/webcore when we
         # can entice gyp into letting us put both the .cpp and .h
         # files in the same output directory.
         '<(SHARED_INTERMEDIATE_DIR)/webcore',
       ],
       'xcode_settings': {
         # Some Mac-specific parts of WebKit won't compile without having this
         # prefix header injected.
         # FIXME: make this a first-class setting.
-        'GCC_PREFIX_HEADER': '../core/WebCorePrefix.h',
+        'GCC_PREFIX_HEADER': '../core/WebCorePrefixMac.h',
       },
       'sources': [
         '<@(derived_sources_aggregate_files)',
         '<@(bindings_files)',
       ],
       'conditions': [
         ['OS=="win"', {
           # In generated bindings code: 'switch contains default but no case'.
           # Disable c4267 warnings until we fix size_t to int truncations.
           'msvs_disabled_warnings': [ 4065, 4267 ],
         }],
         ['OS in ("linux", "android") and "WTF_USE_WEBAUDIO_IPP=1" in feature_defines', {
           'cflags': [
             '<!@(pkg-config --cflags-only-I ipp)',
           ],
         }],
       ],
     },
   ],
 }