Disable UDPSocketPosixTest.WriteAsyncBasicDelay on iOS

because it is flaky

TBR=mmenke@chromium.org

Bug: 934778
Change-Id: I06f222489a3bcc61d6b5b6f2ce2b7f3559ad65aa
Reviewed-on: https://chromium-review.googlesource.com/c/1483051
Commit-Queue: Christos Froussios <cfroussios@chromium.org>
Reviewed-by: Christos Froussios <cfroussios@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634626}

net/socket/udp_socket_posix_unittest.cc

@@ -658,7 +658,13 @@ TEST_F(UDPSocketPosixTest, WriteAsyncNoBatchingError) {
   EXPECT_EQ(ERR_INVALID_HANDLE, rv);
 }
 
-TEST_F(UDPSocketPosixTest, WriteAsyncBasicDelay) {
+#if defined(OS_IOS)
+#define MAYBE_WriteAsyncBasicDelay DISABLED_WriteAsyncBasicDelay
+#else
+#define MAYBE_WriteAsyncBasicDelay WriteAsyncBasicDelay
+#endif
+// TODO(crbug.com/934778) The test is flaky on iOS.
+TEST_F(UDPSocketPosixTest, MAYBE_WriteAsyncBasicDelay) {
   socket_.SetWriteBatchingActive(true);
   socket_.SetWriteMultiCoreEnabled(true);
   DatagramBuffers buffers;