Revert of Simplify BrowserContext by removing redundant methods.

components/feedback/feedback_uploader_chrome_unittest.cc

 // Copyright 2015 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 "components/feedback/feedback_uploader_chrome.h"
 
 #include <string>
 
 #include "base/macros.h"
+#include "base/message_loop/message_loop.h"
 #include "base/metrics/field_trial.h"
 #include "components/variations/variations_associated_data.h"
 #include "components/variations/variations_http_header_provider.h"
 #include "content/public/test/test_browser_context.h"
-#include "content/public/test/test_browser_thread_bundle.h"
 #include "net/url_request/test_url_fetcher_factory.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace feedback {
 
 class FeedbackUploaderChromeTest : public ::testing::Test {
  protected:
-  FeedbackUploaderChromeTest()
-      : browser_thread_bundle_(content::TestBrowserThreadBundle::IO_MAINLOOP) {}
+  FeedbackUploaderChromeTest() {}
 
   ~FeedbackUploaderChromeTest() override {
     // Clean up registered ids.
     variations::testing::ClearAllVariationIDs();
   }
 
   // Registers a field trial with the specified name and group and an associated
   // google web property variation id.
   void CreateFieldTrialWithId(const std::string& trial_name,
                               const std::string& group_name,
                               int variation_id) {
     variations::AssociateGoogleVariationID(
         variations::GOOGLE_WEB_PROPERTIES, trial_name, group_name,
         static_cast<variations::VariationID>(variation_id));
     base::FieldTrialList::CreateFieldTrial(trial_name, group_name)->group();
   }
 
  private:
-  content::TestBrowserThreadBundle browser_thread_bundle_;
+  base::MessageLoopForUI message_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(FeedbackUploaderChromeTest);
 };
 
 TEST_F(FeedbackUploaderChromeTest, VariationHeaders) {
   // Register a trial and variation id, so that there is data in variations
   // headers. Also, the variations header provider may have been registered to
   // observe some other field trial list, so reset it.
   variations::VariationsHttpHeaderProvider::GetInstance()->ResetForTesting();
   base::FieldTrialList field_trial_list_(NULL);
@@ skipping 11 matching lines @@
   std::string value;
   EXPECT_TRUE(headers.GetHeader("X-Client-Data", &value));
   EXPECT_FALSE(value.empty());
   // The fetcher's delegate is responsible for freeing the fetcher (and itself).
   fetcher->delegate()->OnURLFetchComplete(fetcher);
 
   variations::VariationsHttpHeaderProvider::GetInstance()->ResetForTesting();
 }
 
 }  // namespace feedback