stagefright: warnings be gone, some are now errors, use clang

Change-Id: I81f438ae444f04c12ae27ae4ef6d073033de172c
diff --git a/include/media/mediametadataretriever.h b/include/media/mediametadataretriever.h
index 08049c4..f655f35 100644
--- a/include/media/mediametadataretriever.h
+++ b/include/media/mediametadataretriever.h
@@ -26,7 +26,7 @@
 namespace android {
 
 class IDataSource;
-class IMediaHTTPService;
+struct IMediaHTTPService;
 class IMediaPlayerService;
 class IMediaMetadataRetriever;