Ensure tests have an active task runner

chrome/browser/extensions/install_tracker_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 "base/files/file_path.h"
 #include "chrome/browser/extensions/active_install_data.h"
 #include "chrome/browser/extensions/install_tracker.h"
 #include "chrome/test/base/testing_profile.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/manifest_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using extensions::ActiveInstallData;
 using extensions::Extension;
 using extensions::ExtensionRegistry;
 using extensions::InstallTracker;
 using extensions::InstallObserver;
@@ skipping 38 matching lines @@
   Profile* profile() { return profile_.get(); }
   InstallTracker* tracker() { return tracker_.get(); }
 
   void VerifyInstallData(const ActiveInstallData& original,
                          const ActiveInstallData& retrieved) {
     EXPECT_EQ(original.extension_id, retrieved.extension_id);
     EXPECT_EQ(original.is_ephemeral, retrieved.is_ephemeral);
     EXPECT_EQ(original.percent_downloaded, retrieved.percent_downloaded);
   }
 
+  content::TestBrowserThreadBundle thread_bundle_;
   scoped_ptr<TestingProfile> profile_;
   scoped_ptr<InstallTracker> tracker_;
 };
 
 // Verifies that active installs are registered and deregistered correctly.
 TEST_F(InstallTrackerTest, AddAndRemoveActiveInstalls) {
   ActiveInstallData install_data1(kExtensionId1);
   install_data1.percent_downloaded = 76;
   ActiveInstallData install_data2(kExtensionId2);
   install_data2.is_ephemeral = true;
@@ skipping 127 matching lines @@
   // Simulate an extension install.
   scoped_refptr<Extension> extension = CreateDummyExtension(kExtensionId1);
   ASSERT_TRUE(extension.get());
   ExtensionRegistry* registry = ExtensionRegistry::Get(profile());
   ASSERT_TRUE(registry);
   registry->AddEnabled(extension);
   registry->TriggerOnInstalled(extension.get(), false);
 
   EXPECT_FALSE(tracker_->GetActiveInstall(kExtensionId1));
 }