exo: Produce an error if get_keyboard_device_configuration is called with a keyboard object that al…

components/exo/keyboard.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/exo/keyboard.h"
 
 #include "components/exo/keyboard_delegate.h"
 #include "components/exo/keyboard_device_configuration_delegate.h"
 #include "components/exo/shell_surface.h"
 #include "components/exo/surface.h"
@@ skipping 96 matching lines @@
     device_configuration_delegate_->OnKeyboardDestroying(this);
   if (focus_)
     focus_->RemoveSurfaceObserver(this);
   auto* helper = WMHelper::GetInstance();
   helper->RemoveFocusObserver(this);
   helper->RemovePostTargetHandler(this);
   helper->RemoveMaximizeModeObserver(this);
   helper->RemoveInputDeviceEventObserver(this);
 }
 
+bool Keyboard::HasDeviceConfigurationDelegate() const {
+  return !!device_configuration_delegate_;
+}
+
 void Keyboard::SetDeviceConfigurationDelegate(
     KeyboardDeviceConfigurationDelegate* delegate) {
   device_configuration_delegate_ = delegate;
   OnKeyboardDeviceConfigurationChanged();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ui::EventHandler overrides:
 
 void Keyboard::OnKeyEvent(ui::KeyEvent* event) {
@@ skipping 105 matching lines @@
     aura::Window* top_level_window = window->GetToplevelWindow();
     if (top_level_window)
       focus = ShellSurface::GetMainSurface(top_level_window);
   }
 
   return focus && delegate_->CanAcceptKeyboardEventsForSurface(focus) ? focus
                                                                       : nullptr;
 }
 
 }  // namespace exo