Disable flaky ConditionalCacheDeletionHelperBrowserTest.TimeAndURL on mac.

chrome/browser/browsing_data/conditional_cache_deletion_helper_browsertest.cc

 // Copyright (c) 2015 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 <memory>
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 227 matching lines @@
   keys.erase("42");
   CompareRemainingKeys(keys);
 }
 
 // Tests that ConditionalCacheDeletionHelper correctly constructs a condition
 // for time and URL.
 //
 // Note: This test depends on the timing in cache backends and can be flaky
 // if those backends are slow. If this turns out to be a problem, consider
 // increasing the |timeout_ms| constant.
-IN_PROC_BROWSER_TEST_F(ConditionalCacheDeletionHelperBrowserTest, TimeAndURL) {
+//
+// Flakily timing out on Mac 10.11: https://crbug.com/646119
+#if defined(OS_MACOSX)
+#define MAYBE_TimeAndURL DISABLED_TimeAndURL
+#else
+#define MAYBE_TimeAndURL TimeAndURL
+#endif
+IN_PROC_BROWSER_TEST_F(ConditionalCacheDeletionHelperBrowserTest,
+                       MAYBE_TimeAndURL) {
   const int64_t timeout_ms = 1;
 
   // Create some entries.
   std::set<std::string> keys;
   keys.insert("https://google.com/index.html");
   keys.insert("https://example.com/foo/bar/icon.png");
   keys.insert("http://chrome.com");
 
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
@@ skipping 41 matching lines @@
       BrowserThread::IO, FROM_HERE,
       base::Bind(&ConditionalCacheDeletionHelperBrowserTest::GetRemainingKeys,
                  base::Unretained(this)));
   WaitForTasksOnIOThread();
 
   keys.insert(newer_keys.begin(), newer_keys.end());
   keys.erase("https://example.com/foo/bar/icon2.png");
   keys.erase("https://example.com/foo/bar/icon3.png");
   CompareRemainingKeys(keys);
 }