[Mac] Remove bug_26964 valgrind suppression.
[Mac] Remove bug_26964 valgrind suppression.

I cannot repro locally, and the bot logs do not show the suppression
ever firing.  Reviewing the specific log, there was a timeout starting
the Chromium subprocess for one test (which failed), I suspect that
the resulting unclean shutdown may be related.

BUG=26964
TEST=valgrind stays green.

Review URL: http://codereview.chromium.org/415002

git-svn-id: http://src.chromium.org/svn/trunk/src@32542 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 805ef0b514ae3d9774f66f3df12bc9a649aeaa98
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