Add allocator interface for use by cdm_adapter

media/cdm/cdm_buffer_impl.cc

-// 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.
-
-#include "media/cdm/cdm_buffer_impl.h"
-
-#include "base/logging.h"
-
-namespace media {
-
-// static
-CdmBuffer* CdmBuffer::Create(uint32_t capacity) {
-  DCHECK(capacity);
-  return new CdmBuffer(capacity);
-}
-
-CdmBuffer::CdmBuffer(uint32_t capacity) : buffer_(capacity), size_(0) {}
-
-CdmBuffer::~CdmBuffer() {}
-
-void CdmBuffer::Destroy() {
-  delete this;
-}
-
-uint32_t CdmBuffer::Capacity() const {
-  return buffer_.size();
-}
-
-uint8_t* CdmBuffer::Data() {
-  return buffer_.data();
-}
-
-void CdmBuffer::SetSize(uint32_t size) {
-  DCHECK(size <= Capacity());
-  size_ = size > Capacity() ? 0 : size;
-}
-
-uint32_t CdmBuffer::Size() const {
-  return size_;
-}
-
-}  // namespace media