Revert of Simplify BrowserContext by removing redundant methods.

components/precache/content/precache_manager_unittest.cc

 // Copyright 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 "components/precache/content/precache_manager.h"
 
 #include <stddef.h>
 
 #include <map>
 #include <set>
@@ skipping 138 matching lines @@
         switches::kPrecacheManifestURLPrefix, kManifestURLPrefix);
 
     // Make the fetch of the precache configuration settings fail. Precaching
     // should still complete normally in this case.
     factory_.SetFakeResponse(GURL(kConfigURL), "",
                              net::HTTP_INTERNAL_SERVER_ERROR,
                              net::URLRequestStatus::FAILED);
   }
 
   // Must be declared first so that it is destroyed last.
+  content::TestBrowserContext browser_context_;
   content::TestBrowserThreadBundle test_browser_thread_bundle_;
-  content::TestBrowserContext browser_context_;
   PrecacheManagerUnderTest precache_manager_;
   TestURLFetcherCallback url_callback_;
   net::FakeURLFetcherFactory factory_;
   TestPrecacheCompletionCallback precache_callback_;
   testing::NiceMock<MockHistoryService> history_service_;
   base::HistogramTester histograms_;
 };
 
 TEST_F(PrecacheManagerTest, StartAndFinishPrecaching) {
   EXPECT_FALSE(precache_manager_.IsPrecaching());
@@ skipping 258 matching lines @@
   expected_histogram_count_map["Precache.Saved"] += 2;
 
   base::MessageLoop::current()->RunUntilIdle();
   EXPECT_THAT(histograms_.GetTotalCountsForPrefix("Precache."),
               ContainerEq(expected_histogram_count_map));
 }
 
 }  // namespace
 
 }  // namespace precache