Introduce CdmContext interface.

media/base/media_keys.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 MEDIA_BASE_MEDIA_KEYS_H_
 #define MEDIA_BASE_MEDIA_KEYS_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
+#include "media/base/cdm_context.h"
 #include "media/base/media_export.h"
 #include "url/gurl.h"
 
 namespace base {
 class Time;
 }
 
 namespace media {
 
 class Decryptor;
 
 template <typename... T>
 class CdmPromiseTemplate;
 
 typedef CdmPromiseTemplate<std::string> NewSessionCdmPromise;
 typedef CdmPromiseTemplate<> SimpleCdmPromise;
 typedef std::vector<std::vector<uint8> > KeyIdsVector;
 typedef CdmPromiseTemplate<KeyIdsVector> KeyIdsPromise;
 
 // Performs media key operations.
 //
 // All key operations are called on the renderer thread. Therefore, these calls
 // should be fast and nonblocking; key events should be fired asynchronously.
-class MEDIA_EXPORT MediaKeys {
+class MEDIA_EXPORT MediaKeys : public CdmContext{

[ddorwin, 2014/11/20 21:31:46]

Should the CDM be a Context or provide a context?

[xhwang, 2014/11/21 01:34:26]

Yes, I also debated on that one. I think it makes more sense for a MediaKeys to
"provide" a CdmConetxt. Using inheritance is convenient and will result in less
code. But I agree we shouldn't sacrifice interface for implementation
convenience.

Done.

  public:
   // Reported to UMA, so never reuse a value!
   // Must be kept in sync with blink::WebMediaPlayerClient::MediaKeyErrorCode
   // (enforced in webmediaplayer_impl.cc).
   // TODO(jrummell): Can this be moved to proxy_decryptor as it should only be
   // used by the prefixed EME code?
   enum KeyError {
     kUnknownError = 1,
     kClientError,
     // The commented v0.1b values below have never been used.
@@ skipping 17 matching lines @@
 
   // Type of license required when creating/loading a session.
   // Must be consistent with the values specified in the spec:
   // https://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#extensions
   enum SessionType {
     TEMPORARY_SESSION,
     PERSISTENT_SESSION
   };
 
   static const uint32 kInvalidSessionId = 0;
-#if defined(ENABLE_BROWSER_CDMS)
-  static const int kInvalidCdmId = 0;
-#endif
 
   MediaKeys();

[ddorwin, 2014/11/20 21:31:46]

ditto

[xhwang, 2014/11/21 01:34:26]

Done.

-  virtual ~MediaKeys();
+  ~MediaKeys() override;
 
   // Provides a server certificate to be used to encrypt messages to the
   // license server.
   virtual void SetServerCertificate(const uint8* certificate_data,
                                     int certificate_data_length,
                                     scoped_ptr<SimpleCdmPromise> promise) = 0;
 
   // Creates a session with the |init_data_type|, |init_data| and |session_type|
   // provided.
   // Note: UpdateSession() and ReleaseSession() should only be called after
@@ skipping 23 matching lines @@
   // Removes stored session data associated with the session specified by
   // |web_session_id|.
   virtual void RemoveSession(const std::string& web_session_id,
                              scoped_ptr<SimpleCdmPromise> promise) = 0;
 
   // Retrieves the key IDs for keys in the session that the CDM knows are
   // currently usable to decrypt media data.
   virtual void GetUsableKeyIds(const std::string& web_session_id,
                                scoped_ptr<KeyIdsPromise> promise) = 0;
 
-  // Gets the Decryptor object associated with the MediaKeys. Returns NULL if
-  // no Decryptor object is associated. The returned object is only guaranteed
-  // to be valid during the MediaKeys' lifetime.
-  virtual Decryptor* GetDecryptor();
-
-#if defined(ENABLE_BROWSER_CDMS)
-  // Returns the CDM ID associated with |this|. May be kInvalidCdmId if no CDM
-  // ID is associated.
-  virtual int GetCdmId() const = 0;
-#endif
+  // CdmContext implementation

[ddorwin, 2014/11/20 21:31:47]

nit: period.

[xhwang, 2014/11/21 01:34:26]

Done.

+  Decryptor* GetDecryptor() override;

[ddorwin, 2014/11/20 21:31:46]

I may have asked this before, but why isn't this just pure virtual requiring all
concrete instances to decide?

[xhwang, 2014/11/21 01:34:26]

Done, so that we won't discuss this again in the future ;)

 
  private:
   DISALLOW_COPY_AND_ASSIGN(MediaKeys);
 };
 
 // Key event callbacks. See the spec for details:
 // https://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#event-summary
 typedef base::Callback<void(const std::string& web_session_id,
                             const std::vector<uint8>& message,
                             const GURL& destination_url)> SessionMessageCB;
@@ skipping 11 matching lines @@
                             bool has_additional_usable_key)>
     SessionKeysChangeCB;
 
 typedef base::Callback<void(const std::string& web_session_id,
                             const base::Time& new_expiry_time)>
     SessionExpirationUpdateCB;
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MEDIA_KEYS_H_