Disable ServiceProcessControlBrowserTest.LaunchAndReconnect on macOS

The test is flaky.

Bug: 978948
Change-Id: Ie875f58d995d2b0b4fa816bed47eeb9da86eb266
Tbr: thestig@chromium.org
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1678849Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672605}

chrome/browser/service_process/service_process_control_browsertest.cc

@@ -218,6 +218,12 @@ IN_PROC_BROWSER_TEST_F(ServiceProcessControlBrowserTest, LaunchAndIPC) {
   EXPECT_TRUE(ServiceProcessControl::GetInstance()->Shutdown());
 }
 
+// Flaky on macOS: https://crbug.com/978948
+#if defined(OS_MACOSX)
+#define MAYBE_LaunchAndReconnect DISABLED_LaunchAndReconnect
+#else
+#define MAYBE_LaunchAndReconnect LaunchAndReconnect
+#endif
 IN_PROC_BROWSER_TEST_F(ServiceProcessControlBrowserTest, LaunchAndReconnect) {
   LaunchServiceProcessControlAndWait();