Build fix: skip conformance/ogles/GL/control_flow/control_flow_009_to_010.html on mac

This only affacts GPU bots.

It's crashing the tab and cause the remainint webgl_conformance tests to all fail.

BUG=322795
TEST=
TBR=bajones@chromium.org,kbr@chromium.org

Review URL: https://codereview.chromium.org/82763012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236948 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236948