Add allocator interface for use by cdm_adapter

media/cdm/simple_cdm_buffer_allocator.h

+// Copyright 2016 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_SIMPLE_CDM_BUFFER_ALLOCATOR_H_
+#define MEDIA_CDM_SIMPLE_CDM_BUFFER_ALLOCATOR_H_
+
+#include <stdint.h>
+
+#include "base/macros.h"
+#include "media/base/media_export.h"
+#include "media/cdm/cdm_buffer_allocator.h"
+
+namespace media {
+
+// This is a simple CdmBufferAllocator that simply allocates a new
+// SimpleCdmBuffer on every Allocate() request. It does not keep track
+// of the memory allocated. The caller is responsible for calling Release()
+// on the buffer when it is no longer needed.
+class MEDIA_EXPORT SimpleCdmBufferAllocator : public CdmBufferAllocator {
+ public:
+  SimpleCdmBufferAllocator();
+  ~SimpleCdmBufferAllocator() override;
+
+  // CdmBufferAllocator implementation.
+  scoped_refptr<CdmBuffer> Allocate(uint32_t capacity) final;
+  void Release(scoped_refptr<CdmBuffer> buffer) final;
+  scoped_ptr<CdmVideoFrame> CreateCdmVideoFrame() final;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SimpleCdmBufferAllocator);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_CDM_SIMPLE_CDM_BUFFER_ALLOCATOR_H_