Unreviewed gardening, mark perf/compositor-touch-hit-rects.html flaky on all platforms

Saw some failures on release for this test previously marked flaky
only on debug, so I created a new bug for this flaky test and marked
it flaky on release.

TBR=rbyers@chromium.org
BUG=339118

Review URL: https://codereview.chromium.org/131103022

git-svn-id: svn://svn.chromium.org/blink/trunk@166033 bbb929c8-8fbe-4397-9dbb-9b2b20218538