Fixing FBO font rendering bug that resulted from using old surface size.

Change-Id: I31d0967bb36ca6ffb6a4c8194597d3c523cfe954
diff --git a/rsFont.h b/rsFont.h
index 679591c..4ca794d 100644
--- a/rsFont.h
+++ b/rsFont.h
@@ -160,6 +160,9 @@
 
 protected:
 
+    float mSurfaceWidth;
+    float mSurfaceHeight;
+
     friend class Font;
 
     struct CacheTextureLine {