Add a hook to be run after eww has rendered a page

* net/eww.el (eww-after-render-hook): New variable.
(eww-render): Use it.

doc/misc/ChangeLog

+2014-11-13  Lars Magne Ingebrigtsen  <larsi@gnus.org>
+
+	* eww.texi (Variable Index): Mention `eww-after-render-hook'.
+
 2014-11-10  Lars Magne Ingebrigtsen  <larsi@gnus.org>
 
 	* eww.texi (Basics): Document `eww-readable'.

doc/misc/eww.texi

@@ -235,6 +235,11 @@ developers started contributing to it as well.
 @node Variable Index
 @unnumbered Variable Index
 
+@vindex eww-after-render-hook
+After eww has rendered the data in the buffer,
+@code{eww-after-render-hook} is called.  It can be used to alter the
+contents, for instance.
+
 @printindex vr
 
 @node Lisp Function Index

etc/NEWS

@@ -156,6 +156,9 @@ the like off the page.
 *** You can now use several eww buffers in parallel by renaming eww
 buffers you want to keep separate.
 
+*** `eww-after-render-hook' is now called after eww has rendered
+the data in the buffer.
+
 ** Message mode
 
 *** text/html messages that contain inline image parts will be

lisp/ChangeLog

 2014-11-13  Lars Magne Ingebrigtsen  <larsi@gnus.org>
 
+	* net/eww.el (eww-after-render-hook): New variable.
+	(eww-render): Use it.
+
 	* net/shr.el (shr-descend): Don't descend further than
 	`max-specpdl-size' allows (bug#16587).
 	(shr-depth): New variable.

lisp/net/eww.el

@@ -73,6 +73,12 @@
   :type '(choice (const :tag "Never" nil)
                  regexp))
 
+(defcustom eww-after-render-hook nil
+  "A hook called after eww has finished rendering the buffer."
+  :version "25.1"
+  :group 'eww
+  :type 'hook)
+
 (defcustom eww-form-checkbox-selected-symbol "[X]"
   "Symbol used to represent a selected checkbox.
 See also `eww-form-checkbox-symbol'."
@@ -227,7 +233,8 @@ word(s) will be searched for via `eww-search-prefix'."
 	    (eww-display-raw buffer)
 	    (eww-update-header-line-format)))
 	  (plist-put eww-data :title url)
-	  (setq eww-history-position 0))
+	  (setq eww-history-position 0)
+	  (run-hooks 'eww-after-render-hook))
       (kill-buffer data-buffer))))
 
 (defun eww-parse-headers ()