Add HttpProtocolHandler and convert everything to use it

ios/crnet/crnet_environment.mm

Index: ios/crnet/crnet_environment.mm
diff --git a/ios/crnet/crnet_environment.mm b/ios/crnet/crnet_environment.mm
index 4666593a8e96b9adc932c54538b1ff8a54b96a33..8e16b06bb32a7b695e0e2ed114cc61acdd5f7a6f 100644
--- a/ios/crnet/crnet_environment.mm
+++ b/ios/crnet/crnet_environment.mm
@@ -480,8 +480,9 @@ void CrNetEnvironment::InitializeOnNetworkThread() {
       [NSHTTPCookieStorage sharedHTTPCookieStorage]);
   main_context_->set_cookie_store(cookie_store_.get());
 
-  net::URLRequestJobFactoryImpl* job_factory =
-      new net::URLRequestJobFactoryImpl;
+  // TODO(mgersh): Fix this leak too. See https://crbug.com/523858
+  std::unique_ptr<net::URLRequestJobFactoryImpl> job_factory =
+      net::URLRequestJobFactoryImpl::CreateWithHttpProtocolHandlers();
   job_factory->SetProtocolHandler(
       "data", base::WrapUnique(new net::DataProtocolHandler));
 #if !defined(DISABLE_FILE_SUPPORT)
@@ -489,8 +490,7 @@ void CrNetEnvironment::InitializeOnNetworkThread() {
       "file",
       base::MakeUnique<net::FileProtocolHandler>(file_thread_->task_runner()));
 #endif   // !defined(DISABLE_FILE_SUPPORT)
-  main_context_->set_job_factory(job_factory);
-
+  main_context_->set_job_factory(job_factory.release());
   main_context_->set_net_log(net_log_.get());
 }