Add black background to ARC maximzied window as well as fullscreen.

components/exo/shell_surface.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/shell_surface.h"
 
 #include <algorithm>
 
 #include "ash/common/frame/custom_frame_view_ash.h"
 #include "ash/common/shelf/wm_shelf.h"
@@ skipping 1499 matching lines @@
         window->AddChild(shadow_underlay_);
         window->StackChildAtBottom(shadow_underlay_);
       }
     }
 
     bool underlay_capture_events =
         WMHelper::GetInstance()->IsSpokenFeedbackEnabled() &&
         widget_->IsActive();
 
     float shadow_underlay_opacity = shadow_background_opacity_;
+
     // Put the black background layer behind the window if
-    // 1) the window is in immersive fullscreen or is active with
+    // 1) the window is in immersive fullscreen, maximized or is active with
     //    spoken feedback enabled.
     // 2) the window can control the bounds of the window in fullscreen (
     //    thus the background can be visible).
     // 3) the window has no transform (the transformed background may
     //    not cover the entire background, e.g. overview mode).
-    if ((widget_->IsFullscreen() || underlay_capture_events) &&
+    if ((widget_->IsFullscreen() || widget_->IsMaximized() ||
+         underlay_capture_events) &&
         ash::wm::GetWindowState(window)->allow_set_bounds_in_maximized() &&
         window->layer()->GetTargetTransform().IsIdentity()) {
       if (shadow_underlay_in_surface_) {
         shadow_underlay_bounds = gfx::Rect(surface_->window()->bounds().size());
       } else {
         gfx::Point origin;
         origin -= window->bounds().origin().OffsetFromOrigin();
         shadow_bounds.set_origin(origin);
         shadow_bounds.set_size(window->parent()->bounds().size());
       }
@@ skipping 47 matching lines @@
     // small style shadow for them.
     if (!activatable_)
       shadow->SetElevation(wm::ShadowElevation::SMALL);
     // We don't have rounded corners unless frame is enabled.
     if (!frame_enabled_)
       shadow->SetRoundedCornerRadius(0);
   }
 }
 
 }  // namespace exo