A11y: Introduce High Contrast Mode and Screen Magnifier to ubar tray.

ash/system/tray/test_system_tray_delegate.cc

Index: ash/system/tray/test_system_tray_delegate.cc
diff --git a/ash/system/tray/test_system_tray_delegate.cc b/ash/system/tray/test_system_tray_delegate.cc
index 8e0cc6189f281b6ee858907b6aa15e03d4074deb..b72ff6dab9d08ecd576d3f481a41037e02543153 100644
--- a/ash/system/tray/test_system_tray_delegate.cc
+++ b/ash/system/tray/test_system_tray_delegate.cc
@@ -131,6 +131,9 @@ void TestSystemTrayDelegate::ShowIMESettings() {
 void TestSystemTrayDelegate::ShowHelp() {
 }
 
+void TestSystemTrayDelegate::ShowAccessibilityHelp() {
+}
+
 void TestSystemTrayDelegate::ShutDown() {
   MessageLoop::current()->Quit();
 }