Disable offline pages tests on iOS

components/offline_pages/core/background/request_coordinator_unittest.cc

Index: components/offline_pages/core/background/request_coordinator_unittest.cc
diff --git a/components/offline_pages/core/background/request_coordinator_unittest.cc b/components/offline_pages/core/background/request_coordinator_unittest.cc
index b45cf5547f3f5af8a76f2c2aa3958bf21a99eae2..5933792f28b5e73907a93fb8132e263b94a9ac46 100644
--- a/components/offline_pages/core/background/request_coordinator_unittest.cc
+++ b/components/offline_pages/core/background/request_coordinator_unittest.cc
@@ -1301,13 +1301,7 @@ TEST_F(RequestCoordinatorTest, GetAllRequests) {
   EXPECT_EQ(kRequestId2, last_requests().at(1)->request_id());
 }
 
-#if defined(OS_IOS)
-// Flaky on IOS. http://crbug/663311
-#define MAYBE_PauseAndResumeObserver DISABLED_PauseAndResumeObserver
-#else
-#define MAYBE_PauseAndResumeObserver PauseAndResumeObserver
-#endif
-TEST_F(RequestCoordinatorTest, MAYBE_PauseAndResumeObserver) {
+TEST_F(RequestCoordinatorTest, PauseAndResumeObserver) {
   // Set low-end device status to actual status.
   SetIsLowEndDeviceForTest(base::SysInfo::IsLowEndDevice());