Do not recursively delete prerenders from within deleting prerenders.

chrome/browser/prerender/prerender_manager.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/browser/prerender/prerender_manager.h"
 
 #include <algorithm>
 #include <functional>
 #include <string>
 #include <vector>
@@ skipping 952 matching lines @@
 
   if (!IsEnabled())
     return NULL;
 
   if ((origin == ORIGIN_LINK_REL_PRERENDER_CROSSDOMAIN ||
        origin == ORIGIN_LINK_REL_PRERENDER_SAMEDOMAIN) &&
       IsGoogleSearchResultURL(referrer.url)) {
     origin = ORIGIN_GWS_PRERENDER;
   }
 
-  DeleteOldEntries();
-  to_delete_prerenders_.clear();
-
   GURL url = url_arg;
   GURL alias_url;
   uint8 experiment = GetQueryStringBasedExperiment(url_arg);
   if (IsControlGroup(experiment) &&
       MaybeGetQueryStringBasedAliasURL(url, &alias_url)) {
     url = alias_url;
   }
 
   // From here on, we will record a FinalStatus so we need to register with the
   // histogram tracking.
@@ skipping 324 matching lines @@
   if (!render_process_host || !render_process_host->GetBrowserContext())
     return NULL;
   Profile* profile = Profile::FromBrowserContext(
       render_process_host->GetBrowserContext());
   if (!profile)
     return NULL;
   return PrerenderManagerFactory::GetInstance()->GetForProfile(profile);
 }
 
 }  // namespace prerender