Disable all the tests that are flaking more than 5% on ChromeOS builders.

chrome/browser/chromeos/login/login_utils_browsertest.cc

Index: chrome/browser/chromeos/login/login_utils_browsertest.cc
diff --git a/chrome/browser/chromeos/login/login_utils_browsertest.cc b/chrome/browser/chromeos/login/login_utils_browsertest.cc
index 5445552f51c70bb436c88e58c54527a11f2ca23e..227bd8709f85c815897d9e37e556067908cd6baa 100644
--- a/chrome/browser/chromeos/login/login_utils_browsertest.cc
+++ b/chrome/browser/chromeos/login/login_utils_browsertest.cc
@@ -573,7 +573,8 @@ TEST_F(LoginUtilsTest, RlzInitialized) {
 }
 #endif
 
-TEST_P(LoginUtilsBlockingLoginTest, LoginBlocksForUser) {
+// http://crbug.com/396506
+TEST_P(LoginUtilsBlockingLoginTest, DISABLED_LoginBlocksForUser) {
   UserManager* user_manager = UserManager::Get();
   EXPECT_FALSE(user_manager->IsUserLoggedIn());
   EXPECT_FALSE(connector_->IsEnterpriseManaged());