libmediaplayerservice: fix warnings, make warnings errors, use clang

Change-Id: I1b2f6b65c5abbc366068a60b8909104f31b94228
diff --git a/include/media/MediaCodecInfo.h b/include/media/MediaCodecInfo.h
index 895a13a..4067b47 100644
--- a/include/media/MediaCodecInfo.h
+++ b/include/media/MediaCodecInfo.h
@@ -32,7 +32,7 @@
 namespace android {
 
 struct AMessage;
-struct Parcel;
+class Parcel;
 struct CodecCapabilities;
 
 typedef KeyedVector<AString, AString> CodecSettings;