Introduce use_ash macro/gyp define.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/9071013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@116212 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed