extensions: Abstract out install delay strategy

chrome/browser/extensions/extension_gcm_app_handler_unittest.cc

 // Copyright 2014 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_gcm_app_handler.h"
 
 #include <memory>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 248 matching lines @@
     // Create extension service in order to uninstall the extension.
     TestExtensionSystem* extension_system(
         static_cast<TestExtensionSystem*>(ExtensionSystem::Get(profile())));
     base::FilePath extensions_install_dir =
         temp_dir_.path().Append(FILE_PATH_LITERAL("Extensions"));
     extension_system->CreateExtensionService(
         base::CommandLine::ForCurrentProcess(), extensions_install_dir, false);
     extension_service_ = extension_system->Get(profile())->extension_service();
     extension_service_->set_extensions_enabled(true);
     extension_service_->set_show_extensions_prompts(false);
-    extension_service_->set_install_updates_when_idle_for_test(false);
 
     // Create GCMProfileService that talks with fake GCMClient.
     gcm::GCMProfileServiceFactory::GetInstance()->SetTestingFactoryAndUse(
         profile(), &ExtensionGCMAppHandlerTest::BuildGCMProfileService);
 
     // Create a fake version of ExtensionGCMAppHandler.
     gcm_app_handler_.reset(new FakeExtensionGCMAppHandler(profile(), &waiter_));
   }
 
   void TearDown() override {
@@ skipping 209 matching lines @@
 
   // App handler is removed when the extension is updated to the version that
   // has GCM permission removed.
   UpdateExtension(extension.get(), "good2.crx");
   waiter()->PumpUILoop();
   EXPECT_TRUE(gcm_app_handler()->app_handler_count_drop_to_zero());
   EXPECT_FALSE(HasAppHandlers(extension->id()));
 }
 
 }  // namespace extensions