Remove duplicated rule from core.gyp.

Source/core/core.gyp

 #
 # Copyright (C) 2009 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 387 matching lines @@
       'direct_dependent_settings': {
         'defines': [
           'BLINK_IMPLEMENTATION=1',
           'INSIDE_BLINK',
         ],
         'include_dirs': [
           '<@(webcore_include_dirs)',
           '<(DEPTH)/gpu',
           '<(DEPTH)/third_party/angle_dx11/include',
         ],
-        'msvs_disabled_warnings': [
-          4138, 4244, 4291, 4305, 4344, 4355, 4521, 4099,
-        ],
-        'scons_line_length' : 1,
         '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': 'WebCorePrefixMac.h',
         },
       },
       'conditions': [
         ['OS=="win" and component=="shared_library"', {
           'direct_dependent_settings': {
@@ skipping 666 matching lines @@
         '<(SHARED_INTERMEDIATE_DIR)/blink/bindings/V8LayerRect.h',
         '<(SHARED_INTERMEDIATE_DIR)/blink/bindings/V8LayerRectList.cpp',
         '<(SHARED_INTERMEDIATE_DIR)/blink/bindings/V8LayerRectList.h',
       ],
       'sources/': [
         ['exclude', 'testing/js'],
       ],
     },
   ],  # targets
 }