Added support to the Windows cloud print proxy to print XPS documents directl...

chrome/service/cloud_print/print_system.h

Index: chrome/service/cloud_print/print_system.h
===================================================================
--- chrome/service/cloud_print/print_system.h	(revision 74874)
+++ chrome/service/cloud_print/print_system.h	(working copy)
@@ -185,6 +185,11 @@
       const std::string& printer_name) = 0;
   virtual JobSpooler* CreateJobSpooler() = 0;
 
+  // Returns a comma separated list of mimetypes for print data that are
+  // supported by this print system. The format of this string is the same as
+  // that used for the HTTP Accept: header.
+  virtual std::string GetSupportedMimeTypes() = 0;
+
   // Generate unique for proxy.
   static std::string GenerateProxyId();