Restore screen work area after login

ui/keyboard/keyboard_controller_proxy.cc

Index: ui/keyboard/keyboard_controller_proxy.cc
diff --git a/ui/keyboard/keyboard_controller_proxy.cc b/ui/keyboard/keyboard_controller_proxy.cc
index 8923d21a84c4a74f85ffe23fd08a5dd5228401b3..b27642c5228900d5dfc59ee86d63f4df13fdbaa7 100644
--- a/ui/keyboard/keyboard_controller_proxy.cc
+++ b/ui/keyboard/keyboard_controller_proxy.cc
@@ -160,6 +160,10 @@ aura::Window* KeyboardControllerProxy::GetKeyboardWindow() {
   return keyboard_contents_->GetView()->GetNativeView();
 }
 
+bool KeyboardControllerProxy::HasKeyboardWindow() const {
+  return keyboard_contents_;
+}
+
 void KeyboardControllerProxy::ShowKeyboardContainer(aura::Window* container) {
   GetKeyboardWindow()->Show();
   container->Show();