Move discardable memory to //components from //content

content/child/child_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_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_
-#define CONTENT_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_
-
-#include <stddef.h>
-
-#include "base/macros.h"
-#include "base/memory/discardable_memory_allocator.h"
-#include "base/memory/ref_counted.h"
-#include "base/synchronization/lock.h"
-#include "base/trace_event/memory_dump_provider.h"
-#include "content/child/thread_safe_sender.h"
-#include "content/common/content_export.h"
-#include "content/common/discardable_shared_memory_heap.h"
-#include "content/common/host_discardable_shared_memory_manager.h"
-
-namespace content {
-
-// Implementation of DiscardableMemoryAllocator that allocates
-// discardable memory segments through the browser process.
-class CONTENT_EXPORT ChildDiscardableSharedMemoryManager
-    : public base::DiscardableMemoryAllocator,
-      public base::trace_event::MemoryDumpProvider {
- public:
-  explicit ChildDiscardableSharedMemoryManager(ThreadSafeSender* sender);
-  ~ChildDiscardableSharedMemoryManager() override;
-
-  // Overridden from base::DiscardableMemoryAllocator:
-  std::unique_ptr<base::DiscardableMemory> AllocateLockedDiscardableMemory(
-      size_t size) override;
-
-  // Overridden from base::trace_event::MemoryDumpProvider:
-  bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
-                    base::trace_event::ProcessMemoryDump* pmd) override;
-
-  // Release memory and associated resources that have been purged.
-  void ReleaseFreeMemory();
-
-  bool LockSpan(DiscardableSharedMemoryHeap::Span* span);
-  void UnlockSpan(DiscardableSharedMemoryHeap::Span* span);
-  void ReleaseSpan(std::unique_ptr<DiscardableSharedMemoryHeap::Span> span);
-
-  base::trace_event::MemoryAllocatorDump* CreateMemoryAllocatorDump(
-      DiscardableSharedMemoryHeap::Span* span,
-      const char* name,
-      base::trace_event::ProcessMemoryDump* pmd) const;
-
-  struct Statistics {
-    size_t total_size;
-    size_t freelist_size;
-  };
-
-  Statistics GetStatistics() const;
-
- private:
-  std::unique_ptr<base::DiscardableSharedMemory>
-  AllocateLockedDiscardableSharedMemory(size_t size,
-                                        DiscardableSharedMemoryId id);
-  void MemoryUsageChanged(size_t new_bytes_allocated,
-                          size_t new_bytes_free) const;
-
-  mutable base::Lock lock_;
-  DiscardableSharedMemoryHeap heap_;
-  scoped_refptr<ThreadSafeSender> sender_;
-
-  DISALLOW_COPY_AND_ASSIGN(ChildDiscardableSharedMemoryManager);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_CHILD_CHILD_DISCARDABLE_SHARED_MEMORY_MANAGER_H_