Add WebPrescientNetworking to trigger preconnect from Blink.

Source/Platform/chromium/public/WebPrerenderingSupport.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 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WebPrerenderingSupport_h
 #define WebPrerenderingSupport_h
 
 #include "WebCommon.h"
+#include "WebPreconnectMotivation.h"
 
 namespace WebKit {
 
 class WebPrerender;
+class WebURL;
 
 class WebPrerenderingSupport {
 public:
     WEBKIT_EXPORT static void initialize(WebPrerenderingSupport*);
     WEBKIT_EXPORT static void shutdown();
     WEBKIT_EXPORT static WebPrerenderingSupport* current();
 
+    // When a page navigation is speculated, preconnect is triggered to hide
+    // session initialization latency to the server providing the page resource.
+    virtual void preconnect(const WebURL& url,
+                            WebPreconnectMotivation motivation) {}

[kouhei (in TOK), 2013/05/09 03:19:29]

This is to enable Chromium to be compiled before the impl patch land. I am not
sure if this is the right way to do this.

[tkent, 2013/05/09 03:31:16]

It's a common way.
However you should put "{ }" (space between braces) for consistency.

[kouhei (in TOK), 2013/05/09 03:42:55]

Done.

+
     // A prerender link element is added when it is inserted into a document.
     virtual void add(const WebPrerender&) = 0;
 
     // A prerender is canceled when it is removed from a document.
     virtual void cancel(const WebPrerender&) = 0;
 
     // A prerender is abandoned when it's navigated away from or suspended in the page cache. This
     // is a weaker signal than cancel(), since the launcher hasn't indicated that the prerender isn't
     // wanted, and we may end up using it after, for instance, a short redirect chain.
     virtual void abandon(const WebPrerender&) = 0;
 
 protected:
     WebPrerenderingSupport() { }
     virtual ~WebPrerenderingSupport() { }
 
 private:
     static WebPrerenderingSupport* s_platform;
 };
 
 } // namespace WebKit
 
 #endif // WebPrerenderingSupport_h