Load CMA backend from shared library

chromecast/media/base/decrypt_context_clearkey.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 CHROMECAST_MEDIA_BASE_DECRYPT_CONTEXT_CLEARKEY_H_
-#define CHROMECAST_MEDIA_BASE_DECRYPT_CONTEXT_CLEARKEY_H_
-
-#include "base/macros.h"
-#include "chromecast/media/base/decrypt_context.h"
-
-namespace chromecast {
-namespace media {
-
-class DecryptContextClearKey : public DecryptContext {
- public:
-  // Note: DecryptContextClearKey does not take ownership of |key|.
-  explicit DecryptContextClearKey(crypto::SymmetricKey* key);
-
-  // DecryptContext implementation.
-  crypto::SymmetricKey* GetKey() const override;
-
- private:
-  ~DecryptContextClearKey() override;
-
-  crypto::SymmetricKey* const key_;
-
-  DISALLOW_COPY_AND_ASSIGN(DecryptContextClearKey);
-};
-
-}  // namespace media
-}  // namespace chromecast
-
-#endif  // CHROMECAST_MEDIA_BASE_DECRYPT_CONTEXT_CLEARKEY_H_