headless: Make it possible to configure an HTTP proxy

headless/lib/browser/headless_url_request_context_getter.cc

Index: headless/lib/browser/headless_url_request_context_getter.cc
diff --git a/headless/lib/browser/headless_url_request_context_getter.cc b/headless/lib/browser/headless_url_request_context_getter.cc
index de1ad37fcd29dd2d762c1103973b410d70c1adfa..8af00a578adb7d047b186fa2db28dad2ae180366 100644
--- a/headless/lib/browser/headless_url_request_context_getter.cc
+++ b/headless/lib/browser/headless_url_request_context_getter.cc
@@ -85,12 +85,16 @@ HeadlessURLRequestContextGetter::CreateNetworkDelegate() {
 
 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());
 }