Change multi-prerender API to include per launcher slots.

chrome/renderer/prerender/prerender_dispatcher.cc

 // Copyright (c) 2012 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 "chrome/renderer/prerender/prerender_dispatcher.h"
 
 #include "base/logging.h"
 #include "chrome/common/prerender_messages.h"
 #include "chrome/renderer/prerender/prerender_extra_data.h"
 #include "content/public/common/referrer.h"
@@ skipping 40 matching lines @@
   DCHECK_NE(0u, prerenders_.count(prerender_id));
   running_prerender_urls_.insert(
       std::multimap<GURL, int>::value_type(url, prerender_id));
 }
 
 void PrerenderDispatcher::OnPrerenderStop(int prerender_id) {
   DCHECK_NE(0u, prerenders_.count(prerender_id));
   WebPrerender& prerender = prerenders_[prerender_id];
 
   // The prerender should only be null in unit tests.
-  if (!prerender.isNull())
+  if (!prerender.isNull()) {
+    DVLOG(7) << "stopping...";
     prerender.didStopPrerender();
+  } else {
+    DVLOG(7) << "but it was null. :(";
+  }
 
   // TODO(cbentzel): We'd also want to send the map of active prerenders when
   // creating a new render process, so the Add/Remove go relative to that.
   // This may not be that big of a deal in practice, since the newly created tab
   // is unlikely to go to the prerendered page.
   prerenders_.erase(prerender_id);
 
   std::multimap<GURL, int>::iterator it = running_prerender_urls_.begin();
   while (it != running_prerender_urls_.end()) {
     std::multimap<GURL, int>::iterator next = it;
@@ skipping 39 matching lines @@
 }
 
 void PrerenderDispatcher::abandon(const WebPrerender& prerender) {
   const PrerenderExtraData& extra_data =
       PrerenderExtraData::FromPrerender(prerender);
   content::RenderThread::Get()->Send(
       new PrerenderHostMsg_AbandonLinkRelPrerender(extra_data.prerender_id()));
 }
 
 }  // namespace prerender