Start splitting out WebUI into an implementation class and an interface that each page implements...

chrome/browser/ui/webui/about_ui.h

Index: chrome/browser/ui/webui/about_ui.h
===================================================================
--- chrome/browser/ui/webui/about_ui.h	(revision 117388)
+++ chrome/browser/ui/webui/about_ui.h	(working copy)
@@ -11,6 +11,7 @@
 #include "base/basictypes.h"
 #include "chrome/browser/ui/webui/chrome_url_data_manager.h"
 #include "content/browser/webui/web_ui.h"
+#include "content/public/browser/web_ui_controller.h"
 
 class Profile;
 class TabContents;
@@ -43,7 +44,7 @@
   DISALLOW_COPY_AND_ASSIGN(AboutUIHTMLSource);
 };
 
-class AboutUI : public WebUI {
+class AboutUI : public WebUI, public content::WebUIController {
  public:
   explicit AboutUI(content::WebContents* contents, const std::string& host);
   virtual ~AboutUI() {}