Remove ENABLE_WEBGL #define as it's always enabled in Blink

Source/WebKit/chromium/WebKit.gyp

 #
 # Copyright (C) 2011 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 680 matching lines @@
                     ],
                 }, { # else: OS!="android"
                     'sources/': [
                         ['exclude', '/android/'],
                     ],
                 }],
                 ['OS=="mac"', {
                     'include_dirs': [
                         'public/mac',
                     ],
+                    'link_settings': {
+                        'libraries': [
+                            '$(SDKROOT)/System/Library/Frameworks/Accelerate.framework',
+                            '$(SDKROOT)/System/Library/Frameworks/OpenGL.framework',
+                        ],
+                    },
                 }, { # else: OS!="mac"
                     'sources/': [
                         ['exclude', '/mac/'],
                     ],
                 }],
                 ['OS=="win"', {
                     'include_dirs': [
                         'public/win',
                     ],
                 }, { # else: OS!="win"
                     'sources/': [['exclude', '/win/']],
                     'variables': {
                         # FIXME: Turn on warnings on Windows.
                         'chromium_code': 1,
                     }
                 }],
-                ['"ENABLE_WEBGL=1" in feature_defines', {
-                    'conditions': [
-                        ['OS=="mac"', {
-                            'link_settings': {
-                                'libraries': [
-                                    '$(SDKROOT)/System/Library/Frameworks/Accelerate.framework',
-                                    '$(SDKROOT)/System/Library/Frameworks/OpenGL.framework',
-                                ],
-                            },
-                        }],
-                    ],
-                }],
                 ['use_default_render_theme==1', {
                     'include_dirs': [
                         'public/default',
                     ],
                 }, { # else use_default_render_theme==0
                     'sources/': [
                         ['exclude', 'src/default/WebRenderTheme.cpp'],
                         ['exclude', 'public/default/WebRenderTheme.h'],
                     ],
                 }],
@@ skipping 60 matching lines @@
         ['clang==1', {
             'target_defaults': {
                 'cflags': ['-Wglobal-constructors'],
                 'xcode_settings': {
                     'WARNING_CFLAGS': ['-Wglobal-constructors'],
                 },
             },
         }],
     ], # conditions
 }