Update v8 to version 3.7.12.6

BUG=
TEST=


Review URL: http://codereview.chromium.org/8801013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@113028 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -39,7 +39,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.
-  "v8_revision": "10153",
+  "v8_revision": "10163",
   "webrtc_revision": "1027",
   "jsoncpp_revision": "246",
 }