[Mac] Enable zombies for all on devchannel.
[Mac] Enable zombies for all on devchannel.

Attempt to flush out more use-after-free cases in the wild. Right now
messages to freed ObjC objects are binned by the object's address,
with this change they should aggregate into a bigger bin.

BUG=35590, 24987, 45676
TEST=none

Review URL: http://codereview.chromium.org/2627001

git-svn-id: http://src.chromium.org/svn/trunk/src@48933 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: b257ec90b432c733c568e4e9de80c7163822bede
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser