Add support for encrypted WebM files as defined in the RFC.

webkit/media/webmediaplayer_impl.h

Index: webkit/media/webmediaplayer_impl.h
diff --git a/webkit/media/webmediaplayer_impl.h b/webkit/media/webmediaplayer_impl.h
index f01a011d023a68f300f5c945d4bd11dad1b2e790..21f125f98510940d086b12f8e1e26bdeb5795849 100644
--- a/webkit/media/webmediaplayer_impl.h
+++ b/webkit/media/webmediaplayer_impl.h
@@ -70,7 +70,7 @@ class WebFrame;
 }
 
 namespace media {
-class AesDecryptor;
+class HmacAesDecryptor;
 class MediaLog;
 }
 
@@ -277,7 +277,7 @@ class WebMediaPlayerImpl
   bool started_;
 
   // The decryptor that manages decryption keys and decrypts encrypted frames.
-  scoped_ptr<media::AesDecryptor> decryptor_;
+  scoped_ptr<media::HmacAesDecryptor> decryptor_;
 
   scoped_ptr<media::MessageLoopFactory> message_loop_factory_;