Disable flaky test on Mac

Sample failure:
https://ci.chromium.org/p/chromium/builders/ci/Mac10.12%20Tests/38003

TBR=msw@chromium.org

Bug: 1066607
Change-Id: I1fb2fda946b8852ff46a03beac69f8137cd323dc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2437738Reviewed-by: Yi Gu <yigu@chromium.org>
Commit-Queue: Yi Gu <yigu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811706}

chrome/browser/ui/exclusive_access/fullscreen_controller_interactive_browsertest.cc

@@ -420,7 +420,7 @@ IN_PROC_BROWSER_TEST_F(FullscreenControllerInteractiveTest,
 // embedded flash fullscreen, since the Flash plugin handles user permissions
 // requests itself).
 // Flaky on Linux: crbug.com/1066607
-#if defined(OS_LINUX) || defined(OS_CHROMEOS)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(OS_MAC)
 #define MAYBE_PrivilegedMouseLockAndFullscreen \
   DISABLED_PrivilegedMouseLockAndFullscreen
 #else