Implement WebPrescientNetworking to trigger preconnect from Blink

chrome/browser/renderer_host/chrome_render_message_filter.cc

Index: chrome/browser/renderer_host/chrome_render_message_filter.cc
diff --git a/chrome/browser/renderer_host/chrome_render_message_filter.cc b/chrome/browser/renderer_host/chrome_render_message_filter.cc
index 2d25be6e00e746f60bbd4ae4d9eff5650004fd2e..ba19d67844746e6c5e76a9f5e4833e180c24a965 100644
--- a/chrome/browser/renderer_host/chrome_render_message_filter.cc
+++ b/chrome/browser/renderer_host/chrome_render_message_filter.cc
@@ -52,6 +52,7 @@
 using content::BrowserThread;
 using extensions::APIPermission;
 using WebKit::WebCache;
+using chrome_browser_net::UrlInfo;
 
 namespace {
 
@@ -121,6 +122,23 @@ void AddDOMActionToExtensionActivityLog(
   }
 }
 
+UrlInfo::ResolutionMotivation convertWebToUrlInfoMotivation(
+    WebKit::WebPreconnectMotivation webMotivation) {
+  switch(webMotivation) {
+    case WebKit::WebPreconnectMotivationLinkMouseOver:
+      return UrlInfo::MOUSE_OVER_MOTIVATED;
+    case WebKit::WebPreconnectMotivationLinkMouseDown:
+      return UrlInfo::MOUSE_DOWN_MOTIVATED;
+    case WebKit::WebPreconnectMotivationLinkTapUnconfirmed:
+      return UrlInfo::TAP_UNCONFIRMED_MOTIVATED;
+    case WebKit::WebPreconnectMotivationLinkTapDown:
+      return UrlInfo::TAP_DOWN_MOTIVATED;
+    default:
+      NOTREACHED();
+      return UrlInfo::MOUSE_OVER_MOTIVATED;
+  }
+}
+
 } // namespace
 
 ChromeRenderMessageFilter::ChromeRenderMessageFilter(
@@ -155,6 +173,7 @@ bool ChromeRenderMessageFilter::OnMessageReceived(const IPC::Message& message,
                                     OnOpenNaClExecutable)
 #endif
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_DnsPrefetch, OnDnsPrefetch)
+    IPC_MESSAGE_HANDLER(ChromeViewHostMsg_Preconnect, OnPreconnect)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_ResourceTypeStats,
                         OnResourceTypeStats)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_UpdatedCacheStats,
@@ -298,6 +317,17 @@ void ChromeRenderMessageFilter::OnDnsPrefetch(
     profile_->GetNetworkPredictor()->DnsPrefetchList(hostnames);
 }
 
+void ChromeRenderMessageFilter::OnPreconnect(
+    const GURL& url,
+    WebKit::WebPreconnectMotivation motivation,
+    uint32_t motivationVariationId) {
+  if (profile_->GetNetworkPredictor())
+    profile_->GetNetworkPredictor()->PreconnectUrlAndSubresources(
+        url,
+        convertWebToUrlInfoMotivation(motivation),
+        motivationVariationId);
+}
+
 void ChromeRenderMessageFilter::OnResourceTypeStats(
     const WebCache::ResourceTypeStats& stats) {
   HISTOGRAM_COUNTS("WebCoreCache.ImagesSizeKB",