Ensure tests have an active task runner

chrome/browser/bitmap_fetcher/bitmap_fetcher_service_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/bitmap_fetcher/bitmap_fetcher_service.h"
 
 #include "chrome/browser/bitmap_fetcher/bitmap_fetcher.h"
 #include "chrome/test/base/testing_profile.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 class TestNotificationInterface {
  public:
   virtual ~TestNotificationInterface() {}
   virtual void OnImageChanged() = 0;
   virtual void OnRequestFinished() = 0;
 };
@@ skipping 71 matching lines @@
  protected:
   scoped_ptr<BitmapFetcherService> service_;
 
   int imagesChanged_;
   int requestsFinished_;
 
   GURL url1_;
   GURL url2_;
 
  private:
+  content::TestBrowserThreadBundle thread_bundle_;
   TestingProfile profile_;
 };
 
 TEST_F(BitmapFetcherServiceTest, RequestInvalidUrl) {
   const BitmapFetcherService::RequestId invalid_request_id =
       BitmapFetcherService::REQUEST_ID_INVALID;
   GURL invalid_url;
   ASSERT_FALSE(invalid_url.is_valid());
 
   BitmapFetcherService::RequestId request_id =
@@ skipping 52 matching lines @@
   service_->RequestImage(url1_, new TestObserver(this));
   service_->RequestImage(url2_, new TestObserver(this));
   EXPECT_EQ(0U, cache_size());
 
   CompleteFetch(url1_);
   EXPECT_EQ(1U, cache_size());
 
   FailFetch(url2_);
   EXPECT_EQ(1U, cache_size());
 }