First try at a user management screen for the desktop

chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc

Index: chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
diff --git a/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc b/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
index 87d11372a06cd25cfea0d74808f9cab26f874a92..1feeadada6c3c632dc723e605242767e4760dcd8 100644
--- a/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
+++ b/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
@@ -44,6 +44,7 @@
 #include "chrome/browser/ui/webui/profiler_ui.h"
 #include "chrome/browser/ui/webui/quota_internals/quota_internals_ui.h"
 #include "chrome/browser/ui/webui/signin/profile_signin_confirmation_ui.h"
+#include "chrome/browser/ui/webui/signin/user_chooser_ui.h"
 #include "chrome/browser/ui/webui/signin_internals_ui.h"
 #include "chrome/browser/ui/webui/sync_internals_ui.h"
 #include "chrome/browser/ui/webui/translate_internals/translate_internals_ui.h"
@@ -168,6 +169,7 @@ bool NeedsExtensionWebUI(Profile* profile, const GURL& url) {
 WebUIFactoryFunction GetWebUIFactoryFunction(WebUI* web_ui,
                                              Profile* profile,
                                              const GURL& url) {
+
 #if defined(ENABLE_EXTENSIONS)
   if (NeedsExtensionWebUI(profile, url))
     return &NewWebUI<ExtensionWebUI>;
@@ -385,6 +387,11 @@ WebUIFactoryFunction GetWebUIFactoryFunction(WebUI* web_ui,
   }
 #endif
 
+#if !defined(OS_CHROMEOS) && !defined(OS_ANDROID) && !defined(OS_IOS)
+  if (url.host() == chrome::kChromeUIUserChooserHost)
+    return &NewWebUI<UserChooserUI>;
+#endif
+
   if (url.host() == chrome::kChromeUIChromeURLsHost ||
       url.host() == chrome::kChromeUICreditsHost ||
       url.host() == chrome::kChromeUIDNSHost ||