Disable failing PushMessaging browser tests.

chrome/browser/services/gcm/push_messaging_browsertest.cc

Index: chrome/browser/services/gcm/push_messaging_browsertest.cc
diff --git a/chrome/browser/services/gcm/push_messaging_browsertest.cc b/chrome/browser/services/gcm/push_messaging_browsertest.cc
index 5b20c301b8c1b234531234be67fc174e7418ad3b..36c5b913698a240dd2edde9d0776b6e76a3e2ed5 100644
--- a/chrome/browser/services/gcm/push_messaging_browsertest.cc
+++ b/chrome/browser/services/gcm/push_messaging_browsertest.cc
@@ -362,7 +362,8 @@ IN_PROC_BROWSER_TEST_F(PushMessagingBrowserTest, RegisterPersisted) {
   EXPECT_EQ(app_id_sw1.ToString(), gcm_service()->last_registered_app_id());
 }
 
-IN_PROC_BROWSER_TEST_F(PushMessagingBrowserTest, PushEventSuccess) {
+// Disabled due to failures: crbug.com/452666
+IN_PROC_BROWSER_TEST_F(PushMessagingBrowserTest, DISABLED_PushEventSuccess) {
   std::string script_result;
 
   TryToRegisterSuccessfully("1-0" /* expected_push_registration_id */);
@@ -465,8 +466,9 @@ IN_PROC_BROWSER_TEST_F(PushMessagingBrowserTest, PushEventNoPermission) {
 }
 
 #if defined(ENABLE_NOTIFICATIONS)
+// Disabled due to failures: crbug.com/452666
 IN_PROC_BROWSER_TEST_F(PushMessagingBrowserTest,
-                       PushEventEnforcesUserVisibleNotification) {
+                       DISABLED_PushEventEnforcesUserVisibleNotification) {
   std::string script_result;
 
   TryToRegisterSuccessfully("1-0" /* expected_push_registration_id */);