[WIP] Speculatively launch Service Workers on mouse/touch events.

components/network_hints/renderer/renderer_preconnect.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // A RendererPreconnect instance is maintained for each RenderThread.
 // URL strings are typically added to the embedded queue during rendering.
 // The first addition to the queue (transitioning from empty to having
 // some names) causes a processing task to be added to the Renderer Thread.
 // The processing task gathers all buffered URLs, and send them via IPC
 // to the browser.
 // This class counts repeated requests for the same URL and requests that
 // number of connections be preconnected. If multiple requests are sent
 // separately the net stack will just keep re-using the first pending
 // connection so we allow for the time between the parsing of the tags and
 // when the task is scheduled to accumulate multiple requests.
 
 #ifndef COMPONENTS_NETWORK_HINTS_RENDERER_RENDERER_PRECONNECT_H_
 #define COMPONENTS_NETWORK_HINTS_RENDERER_RENDERER_PRECONNECT_H_
 
 #include "base/macros.h"
 #include "url/gurl.h"
 
+namespace blink {
+enum class WebNavigationHintType;
+}
+
 namespace network_hints {
 
 // An internal interface to the network_hints component for efficiently sending
 // preconnect requests to the net stack.
 class RendererPreconnect {
  public:
   RendererPreconnect();
   ~RendererPreconnect();
 
   // Submit a preconnect request for a single connection.
   void Preconnect(const GURL& url, bool allow_credentials);
 
+  // Submit a navigation hint of mouse/touch events to speculatively launche
+  // Service Workers.
+  void NavigationHint(const GURL& url, blink::WebNavigationHintType type);
+
  private:
 
   DISALLOW_COPY_AND_ASSIGN(RendererPreconnect);
 };  // class RendererPreconnect
 
 }  // namespace network_hints
 
 #endif  // COMPONENTS_NETWORK_HINTS_RENDERER_RENDERER_PRECONNECT_H_