Use a utility process for the Mojo v8 proxy resolver.

chrome/browser/net/utility_process_mojo_proxy_resolver_factory.cc

+// 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 "chrome/browser/net/utility_process_mojo_proxy_resolver_factory.h"
+
+#include "base/logging.h"
+#include "base/memory/singleton.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/utility_process_host.h"
+#include "content/public/browser/utility_process_host_client.h"
+#include "content/public/common/service_registry.h"
+#include "net/proxy/mojo_proxy_resolver_factory.h"
+
+// static
+UtilityProcessMojoProxyResolverFactory*
+UtilityProcessMojoProxyResolverFactory::GetInstance() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  return Singleton<
+      UtilityProcessMojoProxyResolverFactory,
+      LeakySingletonTraits<UtilityProcessMojoProxyResolverFactory>>::get();
+}
+
+UtilityProcessMojoProxyResolverFactory::
+    UtilityProcessMojoProxyResolverFactory() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+}
+
+UtilityProcessMojoProxyResolverFactory::
+    ~UtilityProcessMojoProxyResolverFactory() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+}
+
+void UtilityProcessMojoProxyResolverFactory::CreateProcessAndConnect() {
+  DVLOG(1) << "Attempting to create utility process for proxy resolver";
+  content::UtilityProcessHost* utility_process_host =
+      content::UtilityProcessHost::Create(
+          scoped_refptr<content::UtilityProcessHostClient>(),
+          base::MessageLoopProxy::current().get());
+  bool process_started = utility_process_host->StartMojoMode();
+  if (process_started) {
+    content::ServiceRegistry* service_registry =
+        utility_process_host->GetServiceRegistry();
+    service_registry->ConnectToRemoteService(&resolver_factory_);
+    resolver_factory_.set_error_handler(this);
+  } else {
+    LOG(ERROR) << "Unable to connect to utility process";
+  }
+}
+
+void UtilityProcessMojoProxyResolverFactory::Create(
+    mojo::InterfaceRequest<net::interfaces::ProxyResolver> req,
+    net::interfaces::HostResolverPtr host_resolver) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  if (!resolver_factory_)
+    CreateProcessAndConnect();
+
+  if (!resolver_factory_) {
+    // If there's still no factory, then utility process creation failed so
+    // close |req|'s message pipe, which should cause a connection error.
+    req = nullptr;
+    return;
+  }
+  resolver_factory_->CreateResolver(req.Pass(), host_resolver.Pass());
+}
+
+void UtilityProcessMojoProxyResolverFactory::OnConnectionError() {
+  DVLOG(1) << "Disconnection from utility process detected";
+  resolver_factory_.reset();
+}