Generalize AesDecryptor to make it more spec compliant.

media/webm/webm_stream_parser.h

Index: media/webm/webm_stream_parser.h
diff --git a/media/webm/webm_stream_parser.h b/media/webm/webm_stream_parser.h
index 0d37992f9c0ade2cebdb13ac3df299b6476b4177..dae2d24c1f15b779215c3d0d2f801f8f708ad7c3 100644
--- a/media/webm/webm_stream_parser.h
+++ b/media/webm/webm_stream_parser.h
@@ -25,7 +25,7 @@ class WebMStreamParser : public StreamParser {
   virtual void Init(const InitCB& init_cb, const NewConfigCB& config_cb,
                     const NewBuffersCB& audio_cb,
                     const NewBuffersCB& video_cb,
-                    const KeyNeededCB& key_needed_cb) OVERRIDE;
+                    const NeedKeyCB& need_key_cb) OVERRIDE;
   virtual void Flush() OVERRIDE;
   virtual bool Parse(const uint8* buf, int size) OVERRIDE;
 
@@ -63,7 +63,7 @@ class WebMStreamParser : public StreamParser {
   NewConfigCB config_cb_;
   NewBuffersCB audio_cb_;
   NewBuffersCB video_cb_;
-  KeyNeededCB key_needed_cb_;
+  NeedKeyCB need_key_cb_;
 
   scoped_ptr<WebMClusterParser> cluster_parser_;
   ByteQueue byte_queue_;