Disabling BrowserGpuChannelHostFactoryTest.GrContextKeepsGpuChannelAlive on Mac
Disabling BrowserGpuChannelHostFactoryTest.GrContextKeepsGpuChannelAlive on Mac

Test is failing on Mac 10.6 bot.

BUG=551143
TBR=rfevang@chromium.org, loyso@chromium.org, mgiuca@chromium.org

Review URL: https://codereview.chromium.org/1441333002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#359544}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk