PrintPreview: Include <cups/ppd.h> in print_preview_handler.h

This headerfile is required on newer systems.

BUG=none
TEST=print preview works after including the header file.


Review URL: http://codereview.chromium.org/7558008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@95905 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/webui/print_preview_handler.cc

@@ -46,6 +46,7 @@
 
 #if defined(USE_CUPS)
 #include <cups/cups.h>
+#include <cups/ppd.h>
 
 #include "base/file_util.h"
 #endif