Temporarily allow writing to the default malloc zone structure while modifying it.
Temporarily allow writing to the default malloc zone structure while modifying it.

BUG=none
TEST=no crash when launching Chromium next year

Review URL: http://codereview.chromium.org/557084

git-svn-id: http://src.chromium.org/svn/trunk/src@37733 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 80dca7a52c5e50b08d6a4e7771d4faa6e75179ec
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