Add configuration_changed event and set_background_opacity request.

components/exo/shell_surface_unittest.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 "ash/aura/wm_window_aura.h"
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/wm/window_state.h"
 #include "ash/common/wm/wm_event.h"
 #include "ash/common/wm_shell.h"
 #include "ash/wm/window_state_aura.h"
@@ skipping 581 matching lines @@
   aura::Window* window = widget->GetNativeWindow();
 
   // There is no shadow when started in maximized state.
   EXPECT_FALSE(wm::ShadowController::GetShadowForWindow(window));
 
   // Sending a shadow bounds in maximized state won't create a shaodw.
   shell_surface->SetRectangularShadow(gfx::Rect(10, 10, 100, 100));
   surface->Commit();
 
   EXPECT_FALSE(wm::ShadowController::GetShadowForWindow(window));
+  // Underlay should be created even without shadow.
+  ASSERT_TRUE(shell_surface->shadow_underlay_for_test());
+  EXPECT_TRUE(shell_surface->shadow_underlay_for_test()->IsVisible());
 
   // Restore the window and make sure the shadow is created, visible and
   // has the latest bounds.
   widget->Restore();
   wm::Shadow* shadow = wm::ShadowController::GetShadowForWindow(window);
   ASSERT_TRUE(shadow);
   EXPECT_TRUE(shadow->layer()->visible());
   EXPECT_EQ(gfx::Rect(10, 10, 100, 100), shadow->layer()->parent()->bounds());
 }
 
@@ skipping 27 matching lines @@
   // Leave fullscreen mode.
   window->GetWindowState()->OnWMEvent(&event);
 
   // Check that shell surface is maximized.
   EXPECT_EQ(CurrentContext()->bounds().width(),
             shell_surface->GetWidget()->GetWindowBoundsInScreen().width());
 }
 
 }  // namespace
 }  // namespace exo