media: Always define |cdm_id| in CdmContext.

content/renderer/media/crypto/ppapi_decryptor.h

 // Copyright 2013 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_RENDERER_MEDIA_CRYPTO_PPAPI_DECRYPTOR_H_
 #define CONTENT_RENDERER_MEDIA_CRYPTO_PPAPI_DECRYPTOR_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 52 matching lines @@
                      int response_length,
                      scoped_ptr<media::SimpleCdmPromise> promise) override;
   void CloseSession(const std::string& web_session_id,
                     scoped_ptr<media::SimpleCdmPromise> promise) override;
   void RemoveSession(const std::string& web_session_id,
                      scoped_ptr<media::SimpleCdmPromise> promise) override;
   CdmContext* GetCdmContext() override;
 
   // media::CdmContext implementation.
   Decryptor* GetDecryptor() override;
+  int GetCdmId() const override;
 
   // media::Decryptor implementation.
   void RegisterNewKeyCB(StreamType stream_type,
                         const NewKeyCB& key_added_cb) override;
   void Decrypt(StreamType stream_type,
                const scoped_refptr<media::DecoderBuffer>& encrypted,
                const DecryptCB& decrypt_cb) override;
   void CancelDecrypt(StreamType stream_type) override;
   void InitializeAudioDecoder(const media::AudioDecoderConfig& config,
                               const DecoderInitCB& init_cb) override;
@@ skipping 63 matching lines @@
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<PpapiDecryptor> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PpapiDecryptor);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_CRYPTO_PPAPI_DECRYPTOR_H_