Revert of "Speculatively launch Service Workers on mouse/touch events."

components/network_hints/renderer/prescient_networking_dispatcher.cc

 // Copyright 2014 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.
 
 #include "components/network_hints/renderer/prescient_networking_dispatcher.h"
 
 #include "base/logging.h"
-#include "components/network_hints/common/network_hints_messages.h"
-#include "content/public/renderer/render_thread.h"
-
-using content::RenderThread;
 
 namespace network_hints {
 
 PrescientNetworkingDispatcher::PrescientNetworkingDispatcher() {
 }
 
 PrescientNetworkingDispatcher::~PrescientNetworkingDispatcher() {
 }
 
 void PrescientNetworkingDispatcher::prefetchDNS(
     const blink::WebString& hostname) {
   VLOG(2) << "Prefetch DNS: " << hostname.utf8();
   if (hostname.isEmpty())
     return;
 
   std::string hostname_utf8 = hostname.utf8();
   dns_prefetch_.Resolve(hostname_utf8.data(), hostname_utf8.length());
 }
 
 void PrescientNetworkingDispatcher::preconnect(const blink::WebURL& url,
                                                bool allow_credentials) {
   VLOG(2) << "Preconnect: " << url.string().utf8();
   preconnect_.Preconnect(url, allow_credentials);
 }
 
-void PrescientNetworkingDispatcher::sendNavigationHint(
-    const blink::WebURL& url,
-    blink::WebNavigationHintType type) {
-  if (!url.isValid())
-    return;
-  RenderThread::Get()->Send(new NetworkHintsMsg_NavigationHint(url, type));
-}
-
 }  // namespace network_hints