Most Visited: remove over-eager optimization that causes a lot of blank thumbnails

chrome/browser/history/top_sites.cc

 // Copyright (c) 2011 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/history/top_sites.h"
 
 #include <algorithm>
 #include <set>
 
 #include "base/bind.h"
@@ skipping 930 matching lines @@
 void TopSites::ResetThreadSafeCache() {
   base::AutoLock lock(lock_);
   MostVisitedURLList cached;
   ApplyBlacklistAndPinnedURLs(cache_->top_sites(), &cached);
   thread_safe_cache_->SetTopSites(cached);
 }
 
 void TopSites::ResetThreadSafeImageCache() {
   base::AutoLock lock(lock_);
   thread_safe_cache_->SetThumbnails(cache_->images());
-  thread_safe_cache_->RemoveUnreferencedThumbnails();
 }
 
 void TopSites::NotifyTopSitesChanged() {
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_TOP_SITES_CHANGED,
       content::Source<TopSites>(this),
       content::NotificationService::NoDetails());
 }
 
 void TopSites::RestartQueryForTopSitesTimer(base::TimeDelta delta) {
@@ skipping 64 matching lines @@
   SetTopSites(pages);
 
   // Used only in testing.
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_TOP_SITES_UPDATED,
       content::Source<TopSites>(this),
       content::Details<CancelableRequestProvider::Handle>(&handle));
 }
 
 }  // namespace history