Use DiscardableMemoryManager on Android.

base/memory/discardable_memory_ashmem.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_ASHMEM_H_
+#define BASE_MEMORY_DISCARDABLE_MEMORY_ASHMEM_H_
+
+#include "base/memory/discardable_memory.h"
+
+#include "base/basictypes.h"
+#include "base/memory/discardable_memory_manager.h"
+
+namespace base {
+namespace internal {
+
+class DiscardableMemoryAshmem : public DiscardableMemory {
+ public:
+  explicit DiscardableMemoryAshmem(DiscardableMemoryManager* manager,
+                                   size_t size);
+  virtual ~DiscardableMemoryAshmem();
+
+  bool Initialize();
+
+  // DiscardableMemory:
+  virtual DiscardableMemoryLockStatus Lock() OVERRIDE;
+  virtual void Unlock() OVERRIDE;
+  virtual void* Memory() const OVERRIDE;
+
+ private:
+  DiscardableMemoryManager* const manager_;
+  DiscardableMemoryManager::AllocationId allocation_id_;
+  void* memory_;
+
+  DISALLOW_COPY_AND_ASSIGN(DiscardableMemoryAshmem);
+};
+
+}  // namespace internal
+}  // namespace base
+
+#endif  // BASE_MEMORY_DISCARDABLE_MEMORY_ASHMEM_H_