Re-enable PolicyTest.ExtensionInstallBlacklistSelective.

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 1506 matching lines @@
                POLICY_LEVEL_MANDATORY,
                POLICY_SCOPE_USER,
                new base::StringValue(forced_dir.path().value()),
                NULL);
   UpdateProviderPolicy(policies);
   DownloadAndVerifyFile(browser(), forced_dir.path(), file);
   // Verify that the first download location wasn't affected.
   EXPECT_FALSE(base::PathExists(initial_dir.path().Append(file)));
 }
 
-// Flaky: http://crbug.com/388340
-IN_PROC_BROWSER_TEST_F(PolicyTest,
-                       DISABLED_ExtensionInstallBlacklistSelective) {
+IN_PROC_BROWSER_TEST_F(PolicyTest, ExtensionInstallBlacklistSelective) {
   // Verifies that blacklisted extensions can't be installed.
   ExtensionService* service = extension_service();
   ASSERT_FALSE(service->GetExtensionById(kGoodCrxId, true));
   ASSERT_FALSE(service->GetExtensionById(kAdBlockCrxId, true));
   base::ListValue blacklist;
   blacklist.Append(new base::StringValue(kGoodCrxId));
   PolicyMap policies;
   policies.Set(key::kExtensionInstallBlacklist, POLICY_LEVEL_MANDATORY,
                POLICY_SCOPE_USER, blacklist.DeepCopy(), NULL);
   UpdateProviderPolicy(policies);
@@ skipping 1673 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