Implement High Contrast mode for Chrome OS

ash/shell_delegate.h

 // 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.
 
 #ifndef ASH_SHELL_DELEGATE_H_
 #define ASH_SHELL_DELEGATE_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 60 matching lines @@
   // Invoked when the user needs to set up mobile networking.
   virtual void OpenMobileSetup() = 0;
 
   // Get the current browser context. This will get us the current profile.
   virtual content::BrowserContext* GetCurrentBrowserContext() = 0;
 
   // Invoked when the user presses a shortcut to toggle spoken feedback
   // for accessibility.
   virtual void ToggleSpokenFeedback() = 0;
 
+  // Check if High Contrast mode is enabled.
+  virtual bool IsHighContrastEnabled() = 0;
+
   // Invoked to create an AppListViewDelegate. Shell takes the ownership of
   // the created delegate.
   virtual AppListViewDelegate* CreateAppListViewDelegate() = 0;
 
   // Invoked to start taking partial screenshot.
   virtual void StartPartialScreenshot(
       ScreenshotDelegate* screenshot_delegate) = 0;
 
   // Creates a new LauncherDelegate. Shell takes ownership of the returned
   // value.
   virtual LauncherDelegate* CreateLauncherDelegate(
       ash::LauncherModel* model) = 0;
 
   // Creates a system-tray delegate. Shell takes ownership of the delegate.
   virtual SystemTrayDelegate* CreateSystemTrayDelegate(SystemTray* tray) = 0;
 
   // Creates a user wallpaper delegate. Shell takes ownership of the delegate.
   virtual UserWallpaperDelegate* CreateUserWallpaperDelegate() = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_DELEGATE_H_