base: Add free list implementation to browser-wide discardable memory system.

content/common/host_discardable_shared_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 CONTENT_COMMON_HOST_DISCARDABLE_SHARED_MEMORY_MANAGER_H_
 #define CONTENT_COMMON_HOST_DISCARDABLE_SHARED_MEMORY_MANAGER_H_
 
 #include <vector>
 
 #include "base/memory/discardable_memory_shmem_allocator.h"
@@ skipping 15 matching lines @@
 class CONTENT_EXPORT HostDiscardableSharedMemoryManager
     : public base::DiscardableMemoryShmemAllocator {
  public:
   HostDiscardableSharedMemoryManager();
   ~HostDiscardableSharedMemoryManager() override;
 
   // Returns a singleton instance.
   static HostDiscardableSharedMemoryManager* current();
 
   // Overridden from base::DiscardableMemoryShmemAllocator:
-  scoped_ptr<base::DiscardableSharedMemory>
-  AllocateLockedDiscardableSharedMemory(size_t size) override;
+  scoped_ptr<base::DiscardableMemoryShmemChunk> AllocateLockedDiscardableMemory(
+      size_t size) override;
 
   // This allocates a discardable memory segment for |process_handle|.
   // A valid shared memory handle is returned on success.
   void AllocateLockedDiscardableSharedMemoryForChild(
       base::ProcessHandle process_handle,
       size_t size,
       base::SharedMemoryHandle* shared_memory_handle);
 
   // Call this to notify the manager that child process associated with
   // |process_handle| has been removed. The manager will use this to release
@@ skipping 43 matching lines @@
   scoped_ptr<base::MemoryPressureListener> memory_pressure_listener_;
   bool enforce_memory_policy_pending_;
   base::WeakPtrFactory<HostDiscardableSharedMemoryManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HostDiscardableSharedMemoryManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_HOST_DISCARDABLE_SHARED_MEMORY_MANAGER_H_