Make backdrop fully opaque

ash/common/wm/maximize_mode/workspace_backdrop_delegate.cc

 // Copyright 2014 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/common/wm/maximize_mode/workspace_backdrop_delegate.h"
 
 #include "ash/common/wm/workspace/workspace_layout_manager_backdrop_delegate.h"
 #include "ash/common/wm_window.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/root_window_controller.h"
 #include "base/auto_reset.h"
 #include "ui/aura/window_observer.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/views/background.h"
 #include "ui/views/widget/widget.h"
 #include "ui/wm/core/window_animations.h"
 #include "ui/wm/core/window_util.h"
 
 namespace ash {
 namespace {
 
 // The opacity of the backdrop.
-const float kBackdropOpacity = 0.5f;
+const float kBackdropOpacity = 1.0f;
 
 }  // namespace
 
 class WorkspaceBackdropDelegate::WindowObserverImpl
     : public aura::WindowObserver {
  public:
   explicit WindowObserverImpl(WorkspaceBackdropDelegate* delegate)
       : delegate_(delegate) {}
   ~WindowObserverImpl() override {}
 
@@ skipping 133 matching lines @@
 
 void WorkspaceBackdropDelegate::Show() {
   background_window_->GetLayer()->SetOpacity(0.0f);
   background_->Show();
   ui::ScopedLayerAnimationSettings settings(
       background_window_->GetLayer()->GetAnimator());
   background_window_->GetLayer()->SetOpacity(kBackdropOpacity);
 }
 
 }  // namespace ash