Implement High Contrast mode for Chrome OS

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 4731c74c939b8421cdb0f63305c6dfb268695dc5..4ad77696896717100f50d1051250c02260ddc7eb 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -14,6 +14,7 @@
 #include "ash/desktop_background/desktop_background_view.h"
 #include "ash/drag_drop/drag_drop_controller.h"
 #include "ash/focus_cycler.h"
+#include "ash/high_contrast/high_contrast_controller.h"
 #include "ash/launcher/launcher.h"
 #include "ash/magnifier/magnification_controller.h"
 #include "ash/monitor/monitor_controller.h"
@@ -754,6 +755,7 @@ void Shell::Init() {
 
   drag_drop_controller_.reset(new internal::DragDropController);
   magnification_controller_.reset(new internal::MagnificationController);
+  high_contrast_controller_.reset(new HighContrastController);
   power_button_controller_.reset(new PowerButtonController);
   AddShellObserver(power_button_controller_.get());
   video_detector_.reset(new VideoDetector);