Disable AppWindowApiTest.Get on CrOS.

TBR=tapted@chromium.org

Bug: 877129
Change-Id: I86a6136f304f5dde483c9b778ed1a8d058090294
Reviewed-on: https://chromium-review.googlesource.com/1187828Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585845}

extensions/browser/api/app_window/app_window_apitest.cc

@@ -117,7 +117,13 @@ IN_PROC_BROWSER_TEST_F(AppWindowApiTest, AlwaysOnTopNoPermissions) {
       "platform_apps/windows_api_always_on_top/no_permissions")) << message_;
 }
 
-IN_PROC_BROWSER_TEST_F(AppWindowApiTest, Get) {
+// Flaky on CrOS. https://crbug.com/877129
+#if defined(OS_CHROMEOS)
+#define MAYBE_Get DISABLED_Get
+#else
+#define MAYBE_Get Get
+#endif
+IN_PROC_BROWSER_TEST_F(AppWindowApiTest, MAYBE_Get) {
   EXPECT_TRUE(RunPlatformAppTest("platform_apps/windows_api_get"))
       << message_;
 }