headless: Make it possible to configure an HTTP proxy

headless/lib/browser/headless_url_request_context_getter.cc

 // Copyright 2016 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 "headless/lib/browser/headless_url_request_context_getter.h"
 
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/worker_pool.h"
@@ skipping 67 matching lines @@
 
 HeadlessURLRequestContextGetter::~HeadlessURLRequestContextGetter() {}
 
 scoped_ptr<net::NetworkDelegate>
 HeadlessURLRequestContextGetter::CreateNetworkDelegate() {
   return nullptr;
 }
 
 scoped_ptr<net::ProxyConfigService>
 HeadlessURLRequestContextGetter::GetProxyConfigService() {
+  if (!options_.proxy_server.IsEmpty())
+    return nullptr;

[alex clarke (OOO till 29th), 2016/03/14 18:16:08]

Is it worth adding a comment to the definition saying it can return null?

[Sami, 2016/03/14 18:33:27]

Good point, it might be cleaner just to avoid calling this in the first place.

   return net::ProxyService::CreateSystemProxyConfigService(io_task_runner_,
                                                            file_task_runner_);
 }
 
 scoped_ptr<net::ProxyService>
 HeadlessURLRequestContextGetter::GetProxyService() {
+  if (!options_.proxy_server.IsEmpty())
+    return net::ProxyService::CreateFixed(options_.proxy_server.ToString());
   return net::ProxyService::CreateUsingSystemProxyResolver(
       std::move(proxy_config_service_), 0, url_request_context_->net_log());
 }
 
 net::URLRequestContext*
 HeadlessURLRequestContextGetter::GetURLRequestContext() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 
   if (!url_request_context_) {
     const base::CommandLine& command_line =
@@ skipping 109 matching lines @@
 HeadlessURLRequestContextGetter::GetNetworkTaskRunner() const {
   return content::BrowserThread::GetMessageLoopProxyForThread(
       content::BrowserThread::IO);
 }
 
 net::HostResolver* HeadlessURLRequestContextGetter::host_resolver() const {
   return url_request_context_->host_resolver();
 }
 
 }  // namespace headless