Implement WebPrescientNetworking to trigger preconnect from Blink

content/public/renderer/content_renderer_client.h

Index: content/public/renderer/content_renderer_client.h
diff --git a/content/public/renderer/content_renderer_client.h b/content/public/renderer/content_renderer_client.h
index 8d3c7379d2b158d6e71b2ea15778ee6d0685fc28..b0c70a7ae8aa216341e834a53a377962fcf0027b 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -35,6 +35,7 @@ class WebMediaStreamCenterClient;
 class WebMimeRegistry;
 class WebPlugin;
 class WebPluginContainer;
+class WebPrescientNetworking;
 class WebRTCPeerConnectionHandler;
 class WebRTCPeerConnectionHandlerClient;
 class WebSpeechSynthesizer;
@@ -213,6 +214,7 @@ class CONTENT_EXPORT ContentRendererClient {
                                              size_t length);
   virtual bool IsLinkVisited(unsigned long long link_hash);
   virtual void PrefetchHostName(const char* hostname, size_t length) {}
+  virtual WebKit::WebPrescientNetworking* GetPrescientNetworking();

[jam, 2013/06/03 16:41:28]

for WebKit classes that are implemented in src/chrome, we usually don't change
content APIs for them. instead we make chrome set the pointers for these classes
directly, i.e. see 
WebKit::WebAutofillClient
WebKit::WebPrerendererClient
WebKit::WebSpellCheckClient
as some examples, and ChromeContentRendererClient::RenderViewCreated which adds
the chrome implementations at runtime

   virtual bool ShouldOverridePageVisibilityState(
       const RenderView* render_view,
       WebKit::WebPageVisibilityState* override_state) const;