base: Remove OwningMRUCache in favor of scoped_ptrs in MRUCache

ios/chrome/browser/snapshots/lru_cache.mm

 // 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.
 
 #import "ios/chrome/browser/snapshots/lru_cache.h"
 
 #include <stddef.h>
 
 #include "base/containers/hash_tables.h"
 #include "base/containers/mru_cache.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 
 namespace {
 
-class MRUCacheNSObjectDelegate {
- public:
-  MRUCacheNSObjectDelegate(id<LRUCacheDelegate> delegate)
-      : delegate_(delegate) {}
-
-  MRUCacheNSObjectDelegate(const MRUCacheNSObjectDelegate& other) = default;
-
-  void operator()(const base::scoped_nsprotocol<id<NSObject>>& payload) const {
-    [delegate_ lruCacheWillEvictObject:payload.get()];
-  }
-
- private:
-  id<LRUCacheDelegate> delegate_;  // Weak.
-};
-
 struct NSObjectEqualTo {
   bool operator()(const base::scoped_nsprotocol<id<NSObject>>& obj1,
                   const base::scoped_nsprotocol<id<NSObject>>& obj2) const {
     return [obj1 isEqual:obj2];
   }
 };
 
 struct NSObjectHash {
   std::size_t operator()(
       const base::scoped_nsprotocol<id<NSObject>>& obj) const {
     return [obj hash];
   }
 };
 
 template <class KeyType, class ValueType, class HashType>
 struct MRUCacheNSObjectHashMap {
   typedef base::hash_map<KeyType, ValueType, HashType, NSObjectEqualTo> Type;
 };
 
 class NSObjectMRUCache
     : public base::MRUCacheBase<base::scoped_nsprotocol<id<NSObject>>,
                                 base::scoped_nsprotocol<id<NSObject>>,
                                 NSObjectHash,
-                                MRUCacheNSObjectDelegate,
                                 MRUCacheNSObjectHashMap> {
  private:
   typedef base::MRUCacheBase<base::scoped_nsprotocol<id<NSObject>>,
                              base::scoped_nsprotocol<id<NSObject>>,
                              NSObjectHash,
-                             MRUCacheNSObjectDelegate,
                              MRUCacheNSObjectHashMap>
       ParentType;
 
  public:
-  NSObjectMRUCache(typename ParentType::size_type max_size,
-                   const MRUCacheNSObjectDelegate& deletor)
-      : ParentType(max_size, deletor) {}
+  explicit NSObjectMRUCache(typename ParentType::size_type max_size)
+      : ParentType(max_size) {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(NSObjectMRUCache);
 };
 
 }  // namespace
 
-@interface LRUCache ()<LRUCacheDelegate>
-@end
-
 @implementation LRUCache {
   scoped_ptr<NSObjectMRUCache> _cache;
 }
 
-@synthesize delegate = _delegate;
 @synthesize maxCacheSize = _maxCacheSize;
 
 - (instancetype)init {
   NOTREACHED();  // Use initWithCacheSize: instead.
   return nil;
 }
 
 - (instancetype)initWithCacheSize:(NSUInteger)maxCacheSize {
   self = [super init];
   if (self) {
     _maxCacheSize = maxCacheSize;
-    MRUCacheNSObjectDelegate cacheDelegateDeletor(self);
-    _cache.reset(new NSObjectMRUCache(self.maxCacheSize, cacheDelegateDeletor));
+    _cache.reset(new NSObjectMRUCache(self.maxCacheSize));
   }
   return self;
 }
 
 - (id)objectForKey:(id<NSObject>)key {
   base::scoped_nsprotocol<id<NSObject>> keyObj([key retain]);
   auto it = _cache->Get(keyObj);
   if (it == _cache->end())
     return nil;
   return it->second.get();
@@ skipping 17 matching lines @@
 }
 
 - (NSUInteger)count {
   return _cache->size();
 }
 
 - (BOOL)isEmpty {
   return _cache->empty();
 }
 
-#pragma mark - Private
-
-- (void)lruCacheWillEvictObject:(id<NSObject>)obj {
-  [self.delegate lruCacheWillEvictObject:obj];
-}
-
 @end