Move most visited item state info from InstantController to InstantService.

chrome/common/instant_restricted_id_cache.h

 // Copyright 2013 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.
 
 #ifndef CHROME_COMMON_INSTANT_RESTRICTED_ID_CACHE_H_
 #define CHROME_COMMON_INSTANT_RESTRICTED_ID_CACHE_H_
 
 #include <set>
 #include <utility>
 #include <vector>
@@ skipping 51 matching lines @@
   // returns a copy of the item.
   bool GetItemWithRestrictedID(InstantRestrictedID restricted_id,
                                T* item) const;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest, AutoIDGeneration);
   FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest, CrazyIDGeneration);
   FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest, ManualIDGeneration);
   FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest, MixIDGeneration);
   FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest, AddEmptySet);
+  FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest,
+                           AddItemsWithRestrictedID);
 
   typedef base::MRUCache<InstantRestrictedID, T> CacheImpl;
 
   mutable CacheImpl cache_;
   typename CacheImpl::reverse_iterator last_add_start_;
   InstantRestrictedID last_restricted_id_;
 
   DISALLOW_COPY_AND_ASSIGN(InstantRestrictedIDCache);
 };
 
@@ skipping 37 matching lines @@
   }
 
   std::set<InstantRestrictedID> ids_added;
   for (size_t i = 0; i < items.size(); ++i) {
     const ItemIDPair& item_id = items[i];
 
     DCHECK(ids_added.find(item_id.first) == ids_added.end());
     ids_added.insert(item_id.first);
 
     cache_.Put(item_id.first, item_id.second);
-    if (i == 0)
-      last_add_start_ = --cache_.rend();
     last_restricted_id_ = std::max(item_id.first, last_restricted_id_);
   }
+
+  // cache_.Put() can invalidate the iterator |last_add_start_| is pointing to.
+  // Therefore, update |last_add_start_| after adding all the items to the
+  // |cache_|.
+  last_add_start_ = cache_.rend();
+  for (size_t i = 0; i < items.size(); ++i)
+    --last_add_start_;
 }
 
 template <typename T>
 void InstantRestrictedIDCache<T>::GetCurrentItems(ItemIDVector* items) const {
   items->clear();
 
   for (typename CacheImpl::reverse_iterator it = last_add_start_;
        it != cache_.rend(); ++it) {
     items->push_back(std::make_pair(it->first, it->second));
   }
 }
 
 template <typename T>
 bool InstantRestrictedIDCache<T>::GetItemWithRestrictedID(
     InstantRestrictedID restricted_id,
     T* item) const {
   DCHECK(item);
 
   typename CacheImpl::const_iterator cache_it = cache_.Peek(restricted_id);
   if (cache_it == cache_.end())
     return false;
   *item = cache_it->second;
   return true;
 }
 
 #endif  // CHROME_COMMON_INSTANT_RESTRICTED_ID_CACHE_H_