Add WebPrescientNetworking to trigger preconnect from Blink.

Source/Platform/chromium/public/Platform.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 50 matching lines @@
 class WebFlingAnimator;
 class WebGestureCurveTarget;
 class WebGestureCurve;
 class WebGraphicsContext3DProvider;
 class WebHyphenator;
 class WebMediaStreamCenter;
 class WebMediaStreamCenterClient;
 class WebMessagePortChannel;
 class WebMimeRegistry;
 class WebPluginListBuilder;
+class WebPrescientNetworking;
 class WebRTCPeerConnectionHandler;
 class WebRTCPeerConnectionHandlerClient;
 class WebSandboxSupport;
 class WebSocketStreamHandle;
 class WebSpeechSynthesizer;
 class WebSpeechSynthesizerClient;
 class WebStorageNamespace;
 class WebUnitTestSupport;
 class WebThemeEngine;
 class WebThread;
@@ skipping 180 matching lines @@
 
 
     // Network -------------------------------------------------------------
 
     // Returns a new WebURLLoader instance.
     virtual WebURLLoader* createURLLoader() { return 0; }
 
     // A suggestion to prefetch IP information for the given hostname.
     virtual void prefetchHostName(const WebString&) { }
 
+    // May return null.
+    virtual WebPrescientNetworking* prescientNetworking() { return 0; }
+
     // Returns a new WebSocketStreamHandle instance.
     virtual WebSocketStreamHandle* createSocketStreamHandle() { return 0; }
 
     // Returns the User-Agent string that should be used for the given URL.
     virtual WebString userAgent(const WebURL&) { return WebString(); }
 
     // A suggestion to cache this metadata in association with this URL.
     virtual void cacheMetadata(const WebURL&, double responseTime, const char* data, size_t dataSize) { }
 
 
@@ skipping 225 matching lines @@
     virtual void didStartWorkerRunLoop(const WebWorkerRunLoop&) { }
     virtual void didStopWorkerRunLoop(const WebWorkerRunLoop&) { }
 
 protected:
     virtual ~Platform() { }
 };
 
 } // namespace WebKit
 
 #endif