Implement High Contrast mode for Chrome OS

chrome/browser/ui/views/ash/chrome_shell_delegate.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 "chrome/browser/ui/views/ash/chrome_shell_delegate.h"
 
 #include "ash/launcher/launcher_types.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/wm/partial_screenshot_view.h"
 #include "ash/wm/window_util.h"
@@ skipping 189 matching lines @@
   content::WebUI* login_screen_web_ui = NULL;
   chromeos::WebUILoginDisplayHost* host =
       static_cast<chromeos::WebUILoginDisplayHost*>(
           chromeos::BaseLoginDisplayHost::default_host());
   if (host && host->GetOobeUI())
     login_screen_web_ui = host->GetOobeUI()->web_ui();
   chromeos::accessibility::ToggleSpokenFeedback(login_screen_web_ui);
 #endif
 }
 
+bool ChromeShellDelegate::IsHighContrastEnabled() {
+#if defined(OS_CHROMEOS)
+  return chromeos::accessibility::IsHighContrastEnabled();
+#endif
+}
+
 ash::AppListViewDelegate*
     ChromeShellDelegate::CreateAppListViewDelegate() {
   // Shell will own the created delegate.
   return new AppListViewDelegate;
 }
 
 void ChromeShellDelegate::StartPartialScreenshot(
     ash::ScreenshotDelegate* screenshot_delegate) {
   ash::PartialScreenshotView::StartPartialScreenshot(screenshot_delegate);
 }
@@ skipping 32 matching lines @@
       ash::Shell::GetInstance()->CreateLauncher();
       break;
     default:
       NOTREACHED() << "Unexpected notification " << type;
   }
 #else
   // MSVC++ warns about switch statements without any cases.
   NOTREACHED() << "Unexpected notification " << type;
 #endif
 }