Disable failing ExtensionServiceTest.AlertableExtensionHappyPath on chromeos.

chrome/browser/extensions/extension_service_unittest.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 "chrome/browser/extensions/extension_service_unittest.h"
 
 #include <algorithm>
 #include <set>
 #include <vector>
 
@@ skipping 5490 matching lines @@
 
   // Wait for the external source to install.
   WaitForCrxInstall(crx_path_, INSTALL_NEW);
   ASSERT_TRUE(IsCrxInstalled());
 
   // Now that the extension is installed, sync request should fail
   // because the extension is already installed.
   ASSERT_FALSE(AddPendingSyncInstall());
 }
 
+#if !defined(OS_CHROMEOS)
 TEST_F(ExtensionServiceTest, AlertableExtensionHappyPath) {
   InitializeEmptyExtensionService();
   scoped_ptr<ExtensionErrorUI> extension_error_ui(
       ExtensionErrorUI::Create(service_));
   MockExtensionProvider* provider =
       new MockExtensionProvider(service_, Extension::EXTERNAL_PREF);
   AddMockExternalProvider(provider);
 
   // Should return false, meaning there aren't any extensions that the user
   // needs to know about.
@@ skipping 14 matching lines @@
   // This should NOT trigger an alert.
   provider->UpdateOrAddExtension(hosted_app, "1.0.0.0",
                                  data_dir_.AppendASCII("hosted_app.crx"));
 
   service_->CheckForExternalUpdates();
   loop_.RunAllPending();
 
   ASSERT_TRUE(service_->PopulateExtensionErrorUI(extension_error_ui.get()));
   ASSERT_EQ(1u, extension_error_ui->get_external_extension_ids()->size());
 }
+#endif