Disabled DeviceLocalAccountTest.DisplayName for being flaky.

TBR=bartfab@chromium.org,mnissler@chromium.org
NOTRY=true
BUG=512670

Review URL: https://codereview.chromium.org/1241203004

Cr-Commit-Position: refs/heads/master@{#339831}

chrome/browser/chromeos/policy/device_local_account_browsertest.cc

@@ -805,7 +805,8 @@ IN_PROC_BROWSER_TEST_F(DeviceLocalAccountTest, LoginScreen) {
   CheckPublicSessionPresent(user_id_2_);
 }
 
-IN_PROC_BROWSER_TEST_F(DeviceLocalAccountTest, DisplayName) {
+// Flaky: http://crbug.com/512670.
+IN_PROC_BROWSER_TEST_F(DeviceLocalAccountTest, DISABLED_DisplayName) {
   UploadAndInstallDeviceLocalAccountPolicy();
   AddPublicSessionToDevicePolicy(kAccountId1);