Introduce official public NativeWindow type.

Not yet hooked up to anything in the NDK, but requires renaming
the existing android_native_window_t type everywhere.

Change-Id: Iffee6ea39c93b8b34e20fb69e4d2c7c837e5ea2e
diff --git a/libs/rs/rsContext.h b/libs/rs/rsContext.h
index 82c3687..709730e 100644
--- a/libs/rs/rsContext.h
+++ b/libs/rs/rsContext.h
@@ -98,7 +98,7 @@
 
     void pause();
     void resume();
-    void setSurface(uint32_t w, uint32_t h, android_native_window_t *sur);
+    void setSurface(uint32_t w, uint32_t h, ANativeWindow *sur);
     void setPriority(int32_t p);
 
     void assignName(ObjectBase *obj, const char *name, uint32_t len);
@@ -246,7 +246,7 @@
 
     static void * threadProc(void *);
 
-    android_native_window_t *mWndSurface;
+    ANativeWindow *mWndSurface;
 
     Vector<ObjectBase *> mNames;