Implement "Key Presence" step in "Encrypted Block Encounted" algorithm in EME.

webkit/media/crypto/proxy_decryptor.h

 // Copyright (c) 2012 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 WEBKIT_MEDIA_CRYPTO_PROXY_DECRYPTOR_H_
 #define WEBKIT_MEDIA_CRYPTO_PROXY_DECRYPTOR_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 20 matching lines @@
 // forwards decryptor calls to it.
 // TODO(xhwang): Currently we don't support run-time switching among decryptor
 // objects. Fix this when needed.
 class ProxyDecryptor : public media::Decryptor {
  public:
   ProxyDecryptor(media::DecryptorClient* decryptor_client,
                  WebKit::WebMediaPlayerClient* web_media_player_client,
                  WebKit::WebFrame* web_frame);
   virtual ~ProxyDecryptor();
 
+  void set_decryptor_for_testing(scoped_ptr<media::Decryptor> decryptor) {
+    decryptor_ = decryptor.Pass();
+  }
+
   // media::Decryptor implementation.
   virtual void GenerateKeyRequest(const std::string& key_system,
                                   const uint8* init_data,
                                   int init_data_length) OVERRIDE;
   virtual void AddKey(const std::string& key_system,
                       const uint8* key,
                       int key_length,
                       const uint8* init_data,
                       int init_data_length,
                       const std::string& session_id) OVERRIDE;
   virtual void CancelKeyRequest(const std::string& key_system,
                                 const std::string& session_id) OVERRIDE;
   virtual void Decrypt(const scoped_refptr<media::DecoderBuffer>& encrypted,
                        const DecryptCB& decrypt_cb) OVERRIDE;
+  virtual void Stop() OVERRIDE;
 
  private:
   scoped_ptr<media::Decryptor> CreatePpapiDecryptor(
       const std::string& key_system);
   scoped_ptr<media::Decryptor> CreateDecryptor(const std::string& key_system);
 
   // Helper function that makes sure decryptor_->Decrypt() runs on the
   // |message_loop|.
   void DecryptOnMessageLoop(
       const scoped_refptr<base::MessageLoopProxy>& message_loop_proxy,
       const scoped_refptr<media::DecoderBuffer>& encrypted,
       const media::Decryptor::DecryptCB& decrypt_cb);
 
   // Callback used to pass into decryptor_->Decrypt().
   void OnBufferDecrypted(
       const scoped_refptr<base::MessageLoopProxy>& message_loop_proxy,
       const scoped_refptr<media::DecoderBuffer>& encrypted,
       const media::Decryptor::DecryptCB& decrypt_cb,
       media::Decryptor::DecryptStatus status,
       const scoped_refptr<media::DecoderBuffer>& decrypted);
 
   media::DecryptorClient* client_;
 
   // Needed to create the PpapiDecryptor.
   WebKit::WebMediaPlayerClient* web_media_player_client_;
   WebKit::WebFrame* web_frame_;
 
-  // Protects the |decryptor_|. The Decryptor interface specifies that the
-  // Decrypt() function will be called on the decoder thread and all other
-  // methods on the renderer thread. The |decryptor_| itself is thread safe
-  // when this rule is obeyed. This lock is solely to prevent the race condition
-  // between setting the |decryptor_| in GenerateKeyRequest() and using it in
-  // Decrypt().
-  base::Lock decryptor_lock_;
-  scoped_ptr<media::Decryptor> decryptor_;  // Protected by the |lock_|.
-
-  // Protects the |pending_decrypt_closures_|.
-  base::Lock pending_decrypt_closures_lock_;
+  // Protects the |decryptor_| and |pending_decrypt_closures_|. Note that
+  // |decryptor_| itself should be thread safe as per the Decryptor interface.
+  base::Lock lock_;
+  scoped_ptr<media::Decryptor> decryptor_;
   std::vector<base::Closure> pending_decrypt_closures_;
+  bool is_shutting_down_;

[scherkus (not reviewing), 2012/08/02 18:05:32]

nit: use stopped_ instead

[xhwang, 2012/08/03 20:08:10]

Done.

 
   DISALLOW_COPY_AND_ASSIGN(ProxyDecryptor);
 };
 
 }  // namespace webkit_media
 
 #endif  // WEBKIT_MEDIA_CRYPTO_PROXY_DECRYPTOR_H_