Add unit tests for CdmAdapter

media/cdm/aes_decryptor.h

Index: media/cdm/aes_decryptor.h
diff --git a/media/cdm/aes_decryptor.h b/media/cdm/aes_decryptor.h
index 2b5a49ee56998fa716350a3bc34a20101675ca51..b866c5d277c0427fd779be1791fd4f4a9b3541f4 100644
--- a/media/cdm/aes_decryptor.h
+++ b/media/cdm/aes_decryptor.h
@@ -154,6 +154,10 @@ class MEDIA_EXPORT AesDecryptor : public MediaKeys,
   NewKeyCB new_audio_key_cb_;
   NewKeyCB new_video_key_cb_;
 
+  // As AesDecryptor may be in a separate module (e.g. ClearKeyCdm), have a copy
+  // of an empty GURL to avoid leaking the one created by GURL::EmptyGURL().
+  scoped_ptr<GURL> empty_gurl_;
+
   // Protect |new_audio_key_cb_| and |new_video_key_cb_| as they are set on the
   // main thread but called on the media thread.
   mutable base::Lock new_key_cb_lock_;