Update Javadoc for InputConnection.deleteSurroundingText()

- give more precision about how the text is considered

Change-Id: Ie2f09bb3338e7dc0e98da0595d1500a6352d09d3

core/java/android/view/inputmethod/InputConnection.java

@@ -140,7 +140,8 @@ public interface InputConnection {
     /**
      * Delete <var>beforeLength</var> characters of text before the current cursor
      * position, and delete <var>afterLength</var> characters of text after the
-     * current cursor position, excluding composing text.
+     * current cursor position, excluding composing text. Before and after refer
+     * to the order of the characters in the string, not to their visual representation.
      * 
      *
      * @param beforeLength The number of characters to be deleted before the