Add HttpProtocolHandler and convert everything to use it

ios/web/shell/shell_url_request_context_getter.mm

 // 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 "ios/web/shell/shell_url_request_context_getter.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/base_paths.h"
@@ skipping 126 matching lines @@
                                            net::CACHE_BACKEND_DEFAULT,
                                            cache_path, 0, cache_task_runner_));
 
     storage_->set_http_network_session(
         base::WrapUnique(new net::HttpNetworkSession(network_session_params)));
     storage_->set_http_transaction_factory(base::WrapUnique(new net::HttpCache(
         storage_->http_network_session(), std::move(main_backend),
         true /* set_up_quic_server_info */)));
 
     std::unique_ptr<net::URLRequestJobFactoryImpl> job_factory(
-        new net::URLRequestJobFactoryImpl());
+        net::URLRequestJobFactoryImpl::CreateWithDefaultProtocolHandlers());
     bool set_protocol = job_factory->SetProtocolHandler(
         "data", base::WrapUnique(new net::DataProtocolHandler));
     DCHECK(set_protocol);
 
     storage_->set_job_factory(std::move(job_factory));
   }
 
   return url_request_context_.get();
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
 ShellURLRequestContextGetter::GetNetworkTaskRunner() const {
   return network_task_runner_;
 }
 
 }  // namespace web