The handler is first localted by looking at `x-dnd-protocol-alist'.
If no match is found here, and the value of `browse-url-browser-function'
is a pair of (REGEXP . FUNCTION), those regexps are tried for a match.
-If no match is found, just call `x-dnd-insert-text\e,A4\e(B.
+If no match is found, just call `x-dnd-insert-text'.
WINDOW is where the drop happend, ACTION is the action for the drop,
ARG is the URL that has been dropped.
Returns ACTION."