Implement WebPrescientNetworking to trigger preconnect from Blink

chrome/renderer/chrome_content_renderer_client.cc

Index: chrome/renderer/chrome_content_renderer_client.cc
diff --git a/chrome/renderer/chrome_content_renderer_client.cc b/chrome/renderer/chrome_content_renderer_client.cc
index 779c94cf696a0c256cad0190d665385c7f70a459..497c50b07fe6667c1b9bfe0b4fccdb10b6609e50 100644
--- a/chrome/renderer/chrome_content_renderer_client.cc
+++ b/chrome/renderer/chrome_content_renderer_client.cc
@@ -40,6 +40,7 @@
 #include "chrome/renderer/external_extension.h"
 #include "chrome/renderer/loadtimes_extension_bindings.h"
 #include "chrome/renderer/net/net_error_helper.h"
+#include "chrome/renderer/net/prescient_networking_dispatcher.h"
 #include "chrome/renderer/net/renderer_net_predictor.h"
 #include "chrome/renderer/net_benchmarking_extension.h"
 #include "chrome/renderer/one_click_signin_agent.h"
@@ -214,6 +215,7 @@ ChromeContentRendererClient::~ChromeContentRendererClient() {
 void ChromeContentRendererClient::RenderThreadStarted() {
   chrome_observer_.reset(new ChromeRenderProcessObserver(this));
   extension_dispatcher_.reset(new extensions::Dispatcher());
+  prescient_networking_dispatcher_.reset(new PrescientNetworkingDispatcher());
   net_predictor_.reset(new RendererNetPredictor());
   spellcheck_.reset(new SpellCheck());
   visited_link_slave_.reset(new components::VisitedLinkSlave());
@@ -1018,6 +1020,11 @@ void ChromeContentRendererClient::PrefetchHostName(const char* hostname,
   net_predictor_->Resolve(hostname, length);
 }
 
+WebKit::WebPrescientNetworking*
+ChromeContentRendererClient::PrescientNetworking() {
+  return prescient_networking_dispatcher_.get();
+}
+
 bool ChromeContentRendererClient::ShouldOverridePageVisibilityState(
     const content::RenderView* render_view,
     WebKit::WebPageVisibilityState* override_state) const {