Implement High Contrast mode for Chrome OS

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index c2fb5a9f04f16c4077e47751b19f906830fb2ed9..5ec81b7dd6b760b77acda0102af17b773055fa14 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -72,6 +72,7 @@ class AppListController;
 class DragDropController;
 class EventClientImpl;
 class FocusCycler;
+class HighContrastController;
 class KeyRewriterEventFilter;
 class MagnificationController;
 class MonitorController;
@@ -236,9 +237,14 @@ class ASH_EXPORT Shell {
     return user_wallpaper_delegate_.get();
   }
 
+  internal::HighContrastController* high_contrast_controller() {
+    return high_contrast_controller_.get();
+  }
+
   internal::MagnificationController* magnification_controller() {
     return magnification_controller_.get();
   }
+
   internal::ScreenDimmer* screen_dimmer() {
     return screen_dimmer_.get();
   }
@@ -347,6 +353,7 @@ class ASH_EXPORT Shell {
   scoped_ptr<internal::FocusCycler> focus_cycler_;
   scoped_ptr<internal::EventClientImpl> event_client_;
   scoped_ptr<internal::MonitorController> monitor_controller_;
+  scoped_ptr<internal::HighContrastController> high_contrast_controller_;
   scoped_ptr<internal::MagnificationController> magnification_controller_;
   scoped_ptr<internal::ScreenDimmer> screen_dimmer_;