base: Remove OwningMRUCache in favor of scoped_ptrs in MRUCache

ios/chrome/browser/snapshots/lru_cache.h

 // Copyright 2015 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 IOS_CHROME_BROWSER_SNAPSHOTS_LRU_CACHE_H_
 #define IOS_CHROME_BROWSER_SNAPSHOTS_LRU_CACHE_H_
 
 #import <Foundation/Foundation.h>
 
-// The LRUCache delegate is called before an item is evicted from the cache.
-@protocol LRUCacheDelegate
-
-- (void)lruCacheWillEvictObject:(id<NSObject>)object;
-
-@end
-
 // This class implements a cache with a limited size. Once the cache reach its
 // size limit, it will start to evict items in a Least Recently Used order
 // (where the term "used" is determined in terms of query to the cache).
 @interface LRUCache : NSObject
 
-// The delegate of the LRUCache called when objects are evicted from the cache.
-@property(nonatomic, assign) id<LRUCacheDelegate> delegate;
-
 // The maximum amount of items that the cache can hold before starting to
 // evict. The value 0 is used to signify that the cache can hold an unlimited
 // amount of elements (i.e. never evicts).
 @property(nonatomic, readonly) NSUInteger maxCacheSize;
 
 // Use the initWithCacheSize: designated initializer. The is no good general
 // default value for the cache size.
 - (instancetype)init NS_UNAVAILABLE;
 
 // |maxCacheSize| value is used to specify the maximum amount of items that the
 // cache can hold before starting to evict items.
 - (instancetype)initWithCacheSize:(NSUInteger)maxCacheSize
     NS_DESIGNATED_INITIALIZER;
 
 // Query the cache for an item corresponding to the |key|. Returns nil if there
 // is no item corresponding to that key.
 - (id)objectForKey:(id<NSObject>)key;
 
 // Adds the pair |key|, |obj| to the cache. If the value of the maxCacheSize
 // property is non zero, the cache may evict an elements if the maximum cache
 // size is reached. If the |key| is already present in the cache, the value for
-// that key is replaced by |object|. For any evicted object and if the delegate
-// is
-// non nil, it will receive a call to the lruCacheWillEvictObject: selector.
+// that key is replaced by |object|.
 - (void)setObject:(id<NSObject>)object forKey:(NSObject*)key;
 
-// Remove the key, value pair corresponding to the given |key|. If the delegate
-// is non nil, it will receive a call to the lruCacheWillEvictObject: selector.
+// Remove the key, value pair corresponding to the given |key|.
 - (void)removeObjectForKey:(id<NSObject>)key;
 
-// Remove all objects from the cache. For all evicted objects and if the
-// delegate is non nil, it will receive a call to the lruCacheWillEvictObject:
-// selector.
+// Remove all objects from the cache.
 - (void)removeAllObjects;
 
 // Returns the amount of items that the cache currently hold.
 - (NSUInteger)count;
 
 // Returns true if the cache is empty.
 - (BOOL)isEmpty;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_SNAPSHOTS_LRU_CACHE_H_