Fix preprocessor macro for flaky test (BrowserTest.FaviconChange).

BUG=83828
TEST=NONE

Review URL: http://codereview.chromium.org/7075004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86784 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/browser_browsertest.cc

@@ -490,7 +490,7 @@ IN_PROC_BROWSER_TEST_F(BrowserTest,
   EXPECT_EQ(expected_favicon_url.spec(), entry->favicon().url().spec());
 }
 
-#if defined(OS_MAC)
+#if defined(OS_MACOSX)
 // http://crbug.com/83828. On Mac 10.6, the failure rate is 14%
 #define MAYBE_FaviconChange FLAKY_FaviconChange
 #else