64-bit support for Mac OS X in base.

BUG=44127, 18323
TEST=64-bit base should all (mostly) build
Review URL: http://codereview.chromium.org/6708096

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@79069 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed