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 61683ff6eaaee64105646cd741a987ad4cacde28..5f16fbbdcb54ec2c11d7ea8934031499c90bbe0a 100644
--- a/chrome/renderer/chrome_content_renderer_client.cc
+++ b/chrome/renderer/chrome_content_renderer_client.cc
@@ -41,6 +41,7 @@
 #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"
@@ -213,6 +214,7 @@ void ChromeContentRendererClient::RenderThreadStarted() {
   extension_dispatcher_.reset(new extensions::Dispatcher());
   permissions_policy_delegate_.reset(
       new extensions::RendererPermissionsPolicyDelegate());
+  prescient_networking_dispatcher_.reset(new PrescientNetworkingDispatcher());
   net_predictor_.reset(new RendererNetPredictor());
   spellcheck_.reset(new SpellCheck());
   visited_link_slave_.reset(new visitedlink::VisitedLinkSlave());
@@ -1011,6 +1013,11 @@ void ChromeContentRendererClient::PrefetchHostName(const char* hostname,
   net_predictor_->Resolve(hostname, length);
 }
 
+WebKit::WebPrescientNetworking*
+ChromeContentRendererClient::GetPrescientNetworking() {
+  return prescient_networking_dispatcher_.get();
+}
+
 bool ChromeContentRendererClient::ShouldOverridePageVisibilityState(
     const content::RenderView* render_view,
     WebKit::WebPageVisibilityState* override_state) const {