Offer a type-safe album art interface.

Bug: 15514223
Change-Id: Iddfc33a00e6cd3779ca09c01a55f62b151f6ec95
diff --git a/include/media/MediaMetadataRetrieverInterface.h b/include/media/MediaMetadataRetrieverInterface.h
index ecc3b65..cd5bf88 100644
--- a/include/media/MediaMetadataRetrieverInterface.h
+++ b/include/media/MediaMetadataRetrieverInterface.h
@@ -20,6 +20,7 @@
 
 #include <utils/RefBase.h>
 #include <media/mediametadataretriever.h>
+#include <media/mediascanner.h>
 #include <private/media/VideoFrame.h>
 
 namespace android {