Mark gesture-tap-result.html as flaky while we investigate the current
failures.

My appologies for the mess here. I had to revert a number of patches
to get Blink on track again. There seems to be some interaction
between patches hitting us here.

TBR=luken@chromium.org, timav@chromium.org
NOTRY=true
BUG=417229

Review URL: https://codereview.chromium.org/596273002

git-svn-id: svn://svn.chromium.org/blink/trunk@182590 bbb929c8-8fbe-4397-9dbb-9b2b20218538