Disable flaking ChromeLauncherControllerWithArcTest.ArcAppPinPolicy

ChromeLauncherControllerWithArcTest.ArcAppPinPolicy is flaking currently.
Disabling as the team who owns the root cause is OOO.

TEST=ChromeLauncherControllerWithArcTest.ArcAppPinPolicy
TBR=skuhne@chromium.org

Bug: 839916
Change-Id: I86209df361ab53cb84225363c39b1c83db197a2f
Reviewed-on: https://chromium-review.googlesource.com/1044655Reviewed-by: Jonathan Ross <jonross@chromium.org>
Commit-Queue: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556125}

chrome/browser/ui/ash/launcher/chrome_launcher_controller_unittest.cc

@@ -3789,7 +3789,8 @@ TEST_F(ChromeLauncherControllerTest, MultipleAppIconLoaders) {
   EXPECT_EQ(1, app_icon_loader2->clear_count());
 }
 
-TEST_P(ChromeLauncherControllerWithArcTest, ArcAppPinPolicy) {
+// Test is flaking. https://crbug.com/839916
+TEST_P(ChromeLauncherControllerWithArcTest, DISABLED_ArcAppPinPolicy) {
   InitLauncherControllerWithBrowser();
   arc::mojom::AppInfo appinfo =
       CreateAppInfo("Some App", "SomeActivity", "com.example.app");