Disable flaky UnloadTest.CrossSiteInfiniteBeforeUnloadSync on Mac.

chrome/browser/unload_browsertest.cc

Index: chrome/browser/unload_browsertest.cc
diff --git a/chrome/browser/unload_browsertest.cc b/chrome/browser/unload_browsertest.cc
index c19dc051be47a38be733c1ddbff127ef60f4c9d6..98d50973fd3d4a653c22adc25978dbe4c7300796 100644
--- a/chrome/browser/unload_browsertest.cc
+++ b/chrome/browser/unload_browsertest.cc
@@ -238,15 +238,8 @@ IN_PROC_BROWSER_TEST_F(UnloadTest, CrossSiteInfiniteBeforeUnloadAsync) {
 // Navigate to a page with an infinite beforeunload handler.
 // Then two two sync crosssite requests to ensure
 // we correctly nav to each one.
-// Flaky on Win and Linux; http://crbug.com/462671.
-#if defined(OS_WIN) || defined(OS_LINUX)
-#define MAYBE_CrossSiteInfiniteBeforeUnloadSync \
-    DISABLED_CrossSiteInfiniteBeforeUnloadSync
-#else
-#define MAYBE_CrossSiteInfiniteBeforeUnloadSync \
-    CrossSiteInfiniteBeforeUnloadSync
-#endif
-IN_PROC_BROWSER_TEST_F(UnloadTest, MAYBE_CrossSiteInfiniteBeforeUnloadSync) {
+// Flaky on Win, Linux, and Mac; http://crbug.com/462671.
+IN_PROC_BROWSER_TEST_F(UnloadTest, DISABLED_CrossSiteInfiniteBeforeUnloadSync) {
   // Tests makes no sense in single-process mode since the renderer is hung.
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kSingleProcess))