Add HttpProtocolHandler and convert everything to use it

ios/chrome/browser/browser_state/off_the_record_chrome_browser_state_io_data.mm

 // 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 "ios/chrome/browser/browser_state/off_the_record_chrome_browser_state_io_data.h"
 
 #import <UIKit/UIKit.h>
 
 #include <utility>
 
@@ skipping 190 matching lines @@
           cookie_util::CookieStoreConfig::COOKIE_STORE_IOS, nullptr));
   main_context->set_cookie_store(main_cookie_store_.get());
   main_cookie_store_->SetChannelIDServiceID(channel_id_service->GetUniqueID());
 
   http_network_session_ = CreateHttpNetworkSession(*profile_params);
   main_http_factory_ = CreateMainHttpFactory(
       http_network_session_.get(), net::HttpCache::DefaultBackend::InMemory(0));
 
   main_context->set_http_transaction_factory(main_http_factory_.get());
 
-  std::unique_ptr<net::URLRequestJobFactoryImpl> main_job_factory(
-      new net::URLRequestJobFactoryImpl());
+  std::unique_ptr<net::URLRequestJobFactoryImpl> main_job_factory =
+      net::URLRequestJobFactoryImpl::CreateWithDefaultProtocolHandlers();
 
   InstallProtocolHandlers(main_job_factory.get(), protocol_handlers);
   URLRequestInterceptorScopedVector empty_interceptors;
   main_job_factory_ = SetUpJobFactoryDefaults(std::move(main_job_factory),
                                               std::move(empty_interceptors),
                                               main_context->network_delegate());
   main_context->set_job_factory(main_job_factory_.get());
 
   // Setup SDCH for this profile.
   sdch_manager_.reset(new net::SdchManager);
   sdch_policy_.reset(new net::SdchOwner(sdch_manager_.get(), main_context));
   main_context->set_sdch_manager(sdch_manager_.get());
 }
 
 ChromeBrowserStateIOData::AppRequestContext*
 OffTheRecordChromeBrowserStateIOData::InitializeAppRequestContext(
     net::URLRequestContext* main_context) const {
   NOTREACHED();
   return nullptr;
 }
 
 ChromeBrowserStateIOData::AppRequestContext*
 OffTheRecordChromeBrowserStateIOData::AcquireIsolatedAppRequestContext(
     net::URLRequestContext* main_context) const {
   NOTREACHED();
   return nullptr;
 }