Adding RS comments, cleaning up the gl implementation with new Element hal.

Change-Id: I74de1e8248a73a45a39976e6027dac2626d580e9
diff --git a/libs/rs/rsElement.h b/libs/rs/rsElement.h
index 010c612..4b6b460 100644
--- a/libs/rs/rsElement.h
+++ b/libs/rs/rsElement.h
@@ -24,7 +24,14 @@
 // ---------------------------------------------------------------------------
 namespace android {
 namespace renderscript {
-
+/*****************************************************************************
+ * CAUTION
+ *
+ * Any layout changes for this class may require a corresponding change to be
+ * made to frameworks/compile/libbcc/lib/ScriptCRT/rs_core.c, which contains
+ * a partial copy of the information below.
+ *
+ *****************************************************************************/
 // An element is a group of Components that occupies one cell in a structure.
 class Element : public ObjectBase {
 public: