Move WebUIMessageHandler to its own file in the public directory and put it in the content namesp...

chrome/browser/ui/webui/html_dialog_ui.cc

Index: chrome/browser/ui/webui/html_dialog_ui.cc
===================================================================
--- chrome/browser/ui/webui/html_dialog_ui.cc	(revision 116051)
+++ chrome/browser/ui/webui/html_dialog_ui.cc	(working copy)
@@ -13,9 +13,11 @@
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_ui_message_handler.h"
 #include "content/public/common/bindings_policy.h"
 
 using content::WebContents;
+using content::WebUIMessageHandler;
 
 static base::LazyInstance<base::PropertyAccessor<HtmlDialogUIDelegate*> >
     g_html_dialog_ui_property_accessor = LAZY_INSTANCE_INITIALIZER;