Removed ChromeBrowserState::AsTestChromeBrowserState.

ios/chrome/browser/browser_state/test_chrome_browser_state.mm

 // 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 "ios/chrome/browser/browser_state/test_chrome_browser_state.h"
 
 #include <utility>
 
 #include "base/base_paths.h"
 #include "base/files/file_util.h"
@@ skipping 275 matching lines @@
   return new net::TestURLRequestContextGetter(
       web::WebThread::GetTaskRunnerForThread(web::WebThread::IO));
 }
 
 net::URLRequestContextGetter*
 TestChromeBrowserState::CreateIsolatedRequestContext(
     const base::FilePath& partition_path) {
   return nullptr;
 }
 
-TestChromeBrowserState* TestChromeBrowserState::AsTestChromeBrowserState() {
-  return this;
-}
-
 void TestChromeBrowserState::CreateWebDataService() {
   ignore_result(
       ios::WebDataServiceFactory::GetInstance()->SetTestingFactoryAndUse(
           this, &BuildWebDataService));
 
   // Wait a bit after creating the WebDataService to allow the initialisation
   // to complete (otherwise the TestChromeBrowserState may be destroyed before
   // initialisation of the database is complete which leads to SQL init errors).
   base::RunLoop run_loop;
   run_loop.RunUntilIdle();
@@ skipping 106 matching lines @@
   pref_service_ = std::move(prefs);
 }
 
 std::unique_ptr<TestChromeBrowserState>
 TestChromeBrowserState::Builder::Build() {
   DCHECK(!build_called_);
   return base::WrapUnique(new TestChromeBrowserState(
       state_path_, std::move(pref_service_), testing_factories_,
       refcounted_testing_factories_));
 }