[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: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@32542 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser