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

Change-Id: I81f438ae444f04c12ae27ae4ef6d073033de172c
diff --git a/include/media/IStreamSource.h b/include/media/IStreamSource.h
index 149bd49..4a6aafd 100644
--- a/include/media/IStreamSource.h
+++ b/include/media/IStreamSource.h
@@ -23,7 +23,7 @@
 namespace android {
 
 struct AMessage;
-struct IMemory;
+class IMemory;
 struct IStreamListener;
 
 struct IStreamSource : public IInterface {