[Sheriffing] Disable AppShimInteractiveTest.Launch (mac) due to flakiness.

Tbr: ccameron@chromium.org
Bug: 913490
Change-Id: I90fabcfe3bba129fbe2786738c3757526b423a6f
Reviewed-on: https://chromium-review.googlesource.com/c/1369721
Commit-Queue: Samuel Huang <huangs@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615159}

chrome/browser/apps/app_shim/app_shim_interactive_uitest_mac.mm

@@ -291,7 +291,7 @@ namespace apps {
 #define MAYBE_ShowWindow DISABLED_ShowWindow
 #define MAYBE_RebuildShim DISABLED_RebuildShim
 #else
-#define MAYBE_Launch Launch
+#define MAYBE_Launch DISABLED_Launch  // http://crbug.com/913490
 #define MAYBE_HostedAppLaunch DISABLED_HostedAppLaunch
 #define MAYBE_ShowWindow ShowWindow
 // http://crbug.com/517744 HostedAppLaunch fails with open as tab for apps