Add allocator interface for use by cdm_adapter

media/cdm/cdm_buffer_impl.h

-// 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.
-
-#ifndef MEDIA_CDM_CDM_BUFFER_IMPL_H_
-#define MEDIA_CDM_CDM_BUFFER_IMPL_H_
-
-#include <stdint.h>
-
-#include <vector>
-
-#include "base/macros.h"
-#include "media/cdm/api/content_decryption_module.h"
-
-namespace media {
-
-// cdm::Buffer implementation that provides access to memory. This is a simple
-// implementation that stores the data in a std::vector<uint8_t>.
-class CdmBuffer : public cdm::Buffer {
- public:
-  static CdmBuffer* Create(uint32_t capacity);
-
-  // cdm::Buffer implementation.
-  void Destroy() final;
-  uint32_t Capacity() const final;
-  uint8_t* Data() final;
-  void SetSize(uint32_t size) final;
-  uint32_t Size() const final;
-
- private:
-  CdmBuffer(uint32_t capacity);
-  ~CdmBuffer() final;
-
-  std::vector<uint8_t> buffer_;
-  uint32_t size_;
-
-  DISALLOW_COPY_AND_ASSIGN(CdmBuffer);
-};
-
-}  // namespace media
-
-#endif