cros: Break BaseScreenHandler into two classes.

chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc
index 00427f8083bc9501fff78efb40ed08a280418e9c..e20720e8d0e8147d7d4e4d715784590451efd520 100644
--- a/chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc
@@ -55,7 +55,7 @@ namespace chromeos {
 // NetworkScreenHandler, public: -----------------------------------------------
 
 NetworkScreenHandler::NetworkScreenHandler(CoreOobeView* core_oobe_view)
-    : core_oobe_view_(core_oobe_view) {
+    : BaseScreenHandler(kScreenId), core_oobe_view_(core_oobe_view) {
   set_call_js_prefix(kJsScreenPath);
   DCHECK(core_oobe_view_);
 }
@@ -97,7 +97,7 @@ void NetworkScreenHandler::Show() {
   network_screen_params.SetBoolean("isDeveloperMode",
       base::CommandLine::ForCurrentProcess()->HasSwitch(
           chromeos::switches::kSystemDevMode));
-  ShowScreenWithData(OobeScreen::SCREEN_OOBE_NETWORK, &network_screen_params);
+  ShowScreenWithData(kScreenId, &network_screen_params);
   core_oobe_view_->InitDemoModeDetection();
 }