Add WebPrescientNetworking to trigger preconnect from Blink.

Source/WebKit/chromium/tests/PrerenderingTest.cpp

 /*
  * 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 137 matching lines @@
 private:
     class WebPrerenderEqual : public std::binary_function<WebPrerender, WebPrerender, bool> {
     public:
         bool operator()(const WebPrerender& first, const WebPrerender& second) const
         {
             return first.toPrerender() == second.toPrerender();
         }
     };
 
     // From WebPrerenderingSupport:
+    virtual void preconnect(const WebURL& url, WebPreconnectMotivation motivation) OVERRIDE
+    {
+    }
+
     virtual void add(const WebPrerender& prerender) OVERRIDE
     {
         m_addedPrerenders.push_back(prerender);
     }
 
     virtual void cancel(const WebPrerender& prerender) OVERRIDE
     {
         m_canceledPrerenders.push_back(prerender);
     }
 
@@ skipping 324 matching lines @@
     EXPECT_EQ(0u, prerenderingSupport()->cancelCount(webPrerender));
     EXPECT_EQ(1u, prerenderingSupport()->totalCount());
 
     // Change the rel of this prerender, make sure this is treated as a remove.
     executeScript("mutateRel()");
     EXPECT_EQ(1u, prerenderingSupport()->cancelCount(webPrerender));
     EXPECT_EQ(2u, prerenderingSupport()->totalCount());
 }
 
 } // namespace