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

chrome/browser/history/top_sites_cache.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_cache.h"
 
 #include "base/logging.h"
 #include "base/memory/ref_counted_memory.h"
 
 namespace history {
 
 TopSitesCache::TopSitesCache() {
 }
 
 TopSitesCache::~TopSitesCache() {
 }
 
 void TopSitesCache::SetTopSites(const MostVisitedURLList& top_sites) {
   top_sites_ = top_sites;
   GenerateCanonicalURLs();
 }
 
 void TopSitesCache::SetThumbnails(const URLToImagesMap& images) {
   images_ = images;
 }
 
-void TopSitesCache::SetPageThumbnail(const GURL& url,
-                                     RefCountedBytes* thumbnail,
-                                     const ThumbnailScore& score) {
-  Images& img = images_[GetCanonicalURL(url)];
-  img.thumbnail = thumbnail;
-  img.thumbnail_score = score;
-}
-
 Images* TopSitesCache::GetImage(const GURL& url) {
   return &images_[GetCanonicalURL(url)];
 }
 
 bool TopSitesCache::GetPageThumbnail(const GURL& url,
                                      scoped_refptr<RefCountedBytes>* bytes) {
   std::map<GURL, Images>::const_iterator found =
       images_.find(GetCanonicalURL(url));
   if (found != images_.end()) {
     RefCountedBytes* data = found->second.thumbnail.get();
@@ skipping 23 matching lines @@
 
 bool TopSitesCache::IsKnownURL(const GURL& url) {
   return GetCanonicalURLsIterator(url) != canonical_urls_.end();
 }
 
 size_t TopSitesCache::GetURLIndex(const GURL& url) {
   DCHECK(IsKnownURL(url));
   return GetCanonicalURLsIterator(url)->second;
 }
 
-void TopSitesCache::RemoveUnreferencedThumbnails() {
-  for (URLToImagesMap::iterator i = images_.begin(); i != images_.end(); ) {
-    if (IsKnownURL(i->first)) {
-      ++i;
-    } else {
-      URLToImagesMap::iterator next_i = i;
-      ++next_i;
-      images_.erase(i);
-      i = next_i;
-    }
-  }
-}
-
 void TopSitesCache::GenerateCanonicalURLs() {
   canonical_urls_.clear();
   for (size_t i = 0; i < top_sites_.size(); i++)
     StoreRedirectChain(top_sites_[i].redirects, i);
 }
 
 void TopSitesCache::StoreRedirectChain(const RedirectList& redirects,
                                        size_t destination) {
   // redirects is empty if the user pinned a site and there are not enough top
   // sites before the pinned site.
@@ skipping 14 matching lines @@
     const GURL& url) {
   MostVisitedURL most_visited_url;
   most_visited_url.redirects.push_back(url);
   CanonicalURLEntry entry;
   entry.first = &most_visited_url;
   entry.second = 0u;
   return canonical_urls_.find(entry);
 }
 
 }  // namespace history