Disable ExtensionOverrideTest.OverrideNewtab, which is hangy

chrome/browser/extensions/extension_override_apitest.cc

Index: chrome/browser/extensions/extension_override_apitest.cc
diff --git a/chrome/browser/extensions/extension_override_apitest.cc b/chrome/browser/extensions/extension_override_apitest.cc
index 4fd73f41155add50a41c75ea564879114b687edd..634465ba20f180ab42d06cb385dd958e535e76dc 100644
--- a/chrome/browser/extensions/extension_override_apitest.cc
+++ b/chrome/browser/extensions/extension_override_apitest.cc
@@ -72,7 +72,13 @@ IN_PROC_BROWSER_TEST_F(ExtensionOverrideTest, OverrideNewtab) {
   // Verify behavior, then unload the first and verify behavior, etc.
 }
 
-IN_PROC_BROWSER_TEST_F(ExtensionOverrideTest, OverrideNewtabIncognito) {
+#if defined(OS_MACOSX)
+// Hangy: http://crbug.com/70511
+#define MAYBE_OverrideNewtabIncognito DISABLED_OverrideNewtabIncognito
+#else
+#define MAYBE_OverrideNewtabIncognito OverrideNewtabIncognito
+#endif
+IN_PROC_BROWSER_TEST_F(ExtensionOverrideTest, MAYBE_OverrideNewtabIncognito) {
   ASSERT_TRUE(RunExtensionTest("override/newtab")) << message_;
 
   // Navigate an incognito tab to the new tab page.  We should get the actual