Add MediaKeys::GetCdmId().

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>
 
@@ skipping 53 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
   };
 
-  const static uint32 kInvalidSessionId = 0;
+  static const uint32 kInvalidSessionId = 0;
+#if defined(ENABLE_BROWSER_CDMS)
+  static const int kInvalidCdmId = 0;
+#endif
 
   MediaKeys();
   virtual ~MediaKeys();
 
   // 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;
 
@@ skipping 31 matching lines @@
   // 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.
+  int GetCdmId() const;

[ddorwin, 2014/10/17 16:38:56]

Should this be pure virtual to force implementations to implement it rather than
having a default implementation?

[xhwang, 2014/10/17 20:32:06]

Well, most MediaKeys doesn't need this, hence the default implementation. It's
the same as GetDecryptor() above.

[ddorwin, 2014/10/18 17:05:43]

But all implementations that have this define do (or the define is too broad),
right?

[xhwang, 2014/10/20 17:59:53]

AesDecryptor is an exception. But I agree it's clearer not to have the default
impl.

Done.

+#endif
+
  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 10 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_