Add lost -O3 flag when building inside Chromium

TEST=WebKit layout tests no longer timeout

Review URL: http://codereview.chromium.org/7582003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8845 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

tools/gyp/v8.gyp

@@ -192,6 +192,10 @@
                   '-O2',
                   '-Os',
                 ],
+                'cflags': [
+                  '-fomit-frame-pointer',
+                  '-O3',
+                ],
                 'conditions': [
                   [ 'gcc_version==44', {
                     'cflags': [