Disable PolicyTest.FileURLBlacklist on Mac since it's pretty flaky.

chrome/browser/policy/policy_browsertest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 2118 matching lines @@
   {
     base::RunLoop loop;
     BrowserThread::PostTaskAndReply(
         BrowserThread::IO, FROM_HERE,
         base::Bind(UndoRedirectHostsToTestData, kURLS, arraysize(kURLS)),
         loop.QuitClosure());
     loop.Run();
   }
 }
 
-IN_PROC_BROWSER_TEST_F(PolicyTest, FileURLBlacklist) {
+#if defined(OS_MACOSX)
+// http://crbug.com/339240
+#define MAYBE_FileURLBlacklist DISABLED_FileURLBlacklist
+#else
+#define MAYBE_FileURLBlacklist FileURLBlacklist
+#endif
+IN_PROC_BROWSER_TEST_F(PolicyTest, MAYBE_FileURLBlacklist) {
   // Check that FileURLs can be blacklisted and DisabledSchemes works together
   // with URLblacklisting and URLwhitelisting.
 
   base::FilePath test_path;
   PathService::Get(chrome::DIR_TEST_DATA, &test_path);
   const std::string base_path = "file://" + test_path.AsUTF8Unsafe() +"/";
   const std::string folder_path = base_path + "apptest/";
   const std::string file_path1 = base_path + "title1.html";
   const std::string file_path2 = folder_path + "basic.html";
 
@@ skipping 1076 matching lines @@
   EXPECT_TRUE(content::ExecuteScriptAndExtractBool(
       browser2->tab_strip_model()->GetActiveWebContents(),
       "domAutomationController.send(window.showModalDialog !== undefined);",
       &result));
   EXPECT_TRUE(result);
 }
 
 #endif  // !defined(CHROME_OS)
 
 }  // namespace policy