Disable ExtensionApiTest.DisplayModeWindowIsInFullscreen on Mash

Bug: 898169
Change-Id: I2cd883b81a111242691b038ff512652e5faa2a94
Reviewed-on: https://chromium-review.googlesource.com/c/1297055
Reviewed-by: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602073}
1 file changed