Remove usage of deprecate v8::Number constructors from gin

TBR=dcarney@chromium.org
BUG=none

Review URL: https://codereview.chromium.org/109563003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242884 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242884