Fix ExtensionServiceTest.ClearExtensionData flakiness

chrome/browser/extensions/extension_service_unittest.cc

 // Copyright (c) 2013 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 <set>
 #include <vector>
 
 #include "base/at_exit.h"
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/prefs/scoped_user_pref_update.h"
 #include "base/stl_util.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/test/thread_test_helper.h"
 #include "base/version.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/app_sync_data.h"
 #include "chrome/browser/extensions/blacklist.h"
 #include "chrome/browser/extensions/chrome_app_sorting.h"
 #include "chrome/browser/extensions/component_loader.h"
 #include "chrome/browser/extensions/crx_installer.h"
 #include "chrome/browser/extensions/default_apps.h"
 #include "chrome/browser/extensions/extension_creator.h"
@@ skipping 4217 matching lines @@
     base::MessageLoop::current()->PostTask(FROM_HERE,
         base::Bind(&base::MessageLoop::Quit, weak_factory_.GetWeakPtr()));
     list_ = list;
   }
   net::CookieList list_;
   bool result_;
   base::WeakPtrFactory<base::MessageLoop> weak_factory_;
 };
 
 // Verifies extension state is removed upon uninstall.
-#if defined(OS_CHROMEOS)
-// http://crbug.com/396504
-#define MAYBE_ClearExtensionData DISABLED_ClearExtensionData
-#else
-#define MAYBE_ClearExtensionData ClearExtensionData
-#endif
-TEST_F(ExtensionServiceTest, MAYBE_ClearExtensionData) {
+TEST_F(ExtensionServiceTest, ClearExtensionData) {
   InitializeEmptyExtensionService();
   ExtensionCookieCallback callback;
 
   // Load a test extension.
   base::FilePath path = data_dir();
   path = path.AppendASCII("good.crx");
   const Extension* extension = InstallCRX(path, INSTALL_NEW);
   ASSERT_TRUE(extension);
   GURL ext_url(extension->url());
   std::string origin_id = webkit_database::GetIdentifierFromOrigin(ext_url);
@@ skipping 51 matching lines @@
                                       profile())->GetIndexedDBContext();
   idb_context->SetTaskRunnerForTesting(
       base::MessageLoop::current()->message_loop_proxy().get());
   base::FilePath idb_path = idb_context->GetFilePathForTesting(origin_id);
   EXPECT_TRUE(base::CreateDirectory(idb_path));
   EXPECT_TRUE(base::DirectoryExists(idb_path));
 
   // Uninstall the extension.
   service()->UninstallExtension(
       good_crx, extensions::UNINSTALL_REASON_FOR_TESTING, NULL);
+  // The data deletion happens on the IO thread.
+  scoped_refptr<base::ThreadTestHelper> wait_for_io_thread(

[awong, 2014/07/28 15:05:25]

unrelated: Why is ThreadTestHelper refcounted? :-/

+      new base::ThreadTestHelper(
+          content::BrowserThread::GetMessageLoopProxyForThread(
+              content::BrowserThread::IO)));
+  EXPECT_TRUE(wait_for_io_thread->Run());
   base::RunLoop().RunUntilIdle();
 
   // Check that the cookie is gone.
   cookie_monster->GetAllCookiesForURLAsync(
        ext_url,
        base::Bind(&ExtensionCookieCallback::GetAllCookiesCallback,
                   base::Unretained(&callback)));
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ(0U, callback.list_.size());
 
@@ skipping 2669 matching lines @@
 
   service()->Observe(chrome::NOTIFICATION_PROFILE_DESTRUCTION_STARTED,
                      content::Source<Profile>(profile()),
                      content::NotificationService::NoDetails());
   EXPECT_EQ(UnloadedExtensionInfo::REASON_PROFILE_SHUTDOWN, unloaded_reason_);
   EXPECT_EQ(0u, registry()->enabled_extensions().size());
   EXPECT_EQ(0u, registry()->disabled_extensions().size());
   EXPECT_EQ(0u, registry()->terminated_extensions().size());
   EXPECT_EQ(0u, registry()->blacklisted_extensions().size());
 }