Allow setContentDecryptionModule() to get called when setting is done.

media/base/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 MEDIA_BASE_DECRYPTOR_H_
 #define MEDIA_BASE_DECRYPTOR_H_
 
 #include <list>
 
 #include "base/basictypes.h"
@@ skipping 143 matching lines @@
   // This method can be called any time after Initialize{Audio|Video}Decoder()
   // has been called (with the correct stream type).
   // After this operation, the decoder is set to an uninitialized state.
   // The decoder can be reinitialized after it is uninitialized.
   virtual void DeinitializeDecoder(StreamType stream_type) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Decryptor);
 };
 
-// Callback to notify that a decryptor is ready.
-typedef base::Callback<void(Decryptor*)> DecryptorReadyCB;
+// Callback to notify that the decryptor has been completely attached into the
+// pipeline. Parameter indicates whether the operation succeeded.
+typedef base::Callback<void(bool)> DecryptorAttachedCB;
+
+// Callback to notify that a decryptor is ready. DecryptorAttachedCB is called
+// when the decryptor has been completely inserted into the pipeline.
+typedef base::Callback<void(Decryptor*, const DecryptorAttachedCB&)>
+    DecryptorReadyCB;
 
 // Callback to set/cancel a DecryptorReadyCB.
 // Calling this callback with a non-null callback registers decryptor ready
 // notification. When the decryptor is ready, notification will be sent
 // through the provided callback.
 // Calling this callback with a null callback cancels previously registered
 // decryptor ready notification. Any previously provided callback will be
 // fired immediately with NULL.
 typedef base::Callback<void(const DecryptorReadyCB&)> SetDecryptorReadyCB;
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_DECRYPTOR_H_