Add lost -O3 flag when building inside Chromium

tools/gyp/v8.gyp

 # Copyright 2011 the V8 project authors. 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
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 174 matching lines @@
              }],
            ],
           },
           'Release': {
             'conditions': [
               ['OS=="linux" or OS=="freebsd" or OS=="openbsd"', {
                 'cflags!': [
                   '-O2',
                   '-Os',
                 ],
+                'cflags': [
+                  '-fomit-frame-pointer',
+                  '-O3',
+                ],
                 'conditions': [
                   [ 'gcc_version==44', {
                     'cflags': [
                       # Avoid crashes with gcc 4.4 in the v8 test suite.
                       '-fno-tree-vrp',
                     ],
                   }],
                 ],
               }],
              ['OS=="freebsd" or OS=="openbsd"', {
@@ skipping 851 matching lines @@
             }],
           ],
           'dependencies': [
             'v8'
           ],
         },
       ],
     }],
   ],
 }