base: Use DiscardableMemoryManager on MacOSX.

base/memory/discardable_memory_manager.h

 // Copyright 2014 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 BASE_MEMORY_DISCARDABLE_MEMORY_MANAGER_H_
 #define BASE_MEMORY_DISCARDABLE_MEMORY_MANAGER_H_
 
 #include "base/base_export.h"
 #include "base/containers/hash_tables.h"
 #include "base/containers/mru_cache.h"
@@ skipping 49 matching lines @@
 // amount of allocated memory (in case this forces a purge). When memory usage
 // reaches the limit, the manager purges the LRU memory.
 //
 // When notified of memory pressure, the manager either purges the LRU memory --
 // if the pressure is moderate -- or all discardable memory if the pressure is
 // critical.
 class BASE_EXPORT_PRIVATE DiscardableMemoryManager {
  public:
   typedef DiscardableMemoryManagerAllocation Allocation;
 
-  DiscardableMemoryManager();
+  DiscardableMemoryManager(size_t memory_limit,
+                           size_t bytes_to_keep_under_moderate_pressure);
   ~DiscardableMemoryManager();
 
   // Call this to register memory pressure listener. Must be called on a thread
   // with a MessageLoop current.
   void RegisterMemoryPressureListener();
 
   // Call this to unregister memory pressure listener.
   void UnregisterMemoryPressureListener();
 
   // The maximum number of bytes of memory that may be allocated before we force
@@ skipping 82 matching lines @@
   // pressure.
   scoped_ptr<MemoryPressureListener> memory_pressure_listener_;
 
   DISALLOW_COPY_AND_ASSIGN(DiscardableMemoryManager);
 };
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_MEMORY_DISCARDABLE_MEMORY_MANAGER_H_