Implement High Contrast mode for Chrome OS

ash/high_contrast/high_contrast_controller.cc

+// Copyright (c) 2012 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/high_contrast/high_contrast_controller.h"
+
+#include "ash/shell.h"
+#include "ui/aura/root_window.h"
+#include "ui/compositor/layer.h"
+
+namespace ash {
+
+HighContrastController::HighContrastController()
+    : enabled_(false) {
+  root_window_ = ash::Shell::GetRootWindow();
+}
+
+void HighContrastController::SetEnabled(bool enabled) {
+  enabled_ = enabled;
+
+  root_window_->layer()->SetInverted(enabled_);
+}
+
+}  // namespace ash