dom-ui options: Add button for displaying Gears settings (windows only)....

chrome/browser/dom_ui/advanced_options_handler.h

Index: chrome/browser/dom_ui/advanced_options_handler.h
===================================================================
--- chrome/browser/dom_ui/advanced_options_handler.h	(revision 56875)
+++ chrome/browser/dom_ui/advanced_options_handler.h	(working copy)
@@ -54,6 +54,9 @@
   // Callback for the "Use SSL2" checkbox.  This is needed so we can support
   // manual handling on Windows.
   void HandleUseSSL2Checkbox(const ListValue* args);
+
+  // Callback for the "Show Gears Settings" button.
+  void HandleShowGearsSettings(const ListValue* args);
 #endif
 
 #if !defined(OS_CHROMEOS)