Disable flaky LoginApitest.LaunchManagedGuestSession.

TBR=jityao@google.com,voit@google.com

Bug: 1014239
Change-Id: Ic49689798f3c44816c537e2bf26c05c702e5a480
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1859581Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705685}

chrome/browser/chromeos/extensions/login_screen/login/login_apitest.cc

@@ -69,7 +69,8 @@ class LoginApitest : public LoginScreenApitestBase {
   DISALLOW_COPY_AND_ASSIGN(LoginApitest);
 };
 
-IN_PROC_BROWSER_TEST_F(LoginApitest, LaunchManagedGuestSession) {
+// Flaky. https://crbug.com/1014239
+IN_PROC_BROWSER_TEST_F(LoginApitest, DISABLED_LaunchManagedGuestSession) {
   SetUpDeviceLocalAccountPolicy();
   SetUpExtensionAndRunTest(kLaunchManagedGuestSession);
   EXPECT_TRUE(session_manager::SessionManager::Get()->IsSessionStarted());