Add Search+Shift+H as global shortcut to toggle high contrast mode.

ash/common/system/system_notifier.cc

 // Copyright 2013 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 "ash/common/system/system_notifier.h"
 
 #include "base/logging.h"
 
 namespace ash {
 namespace system_notifier {
 
 namespace {
 
 // See http://dev.chromium.org/chromium-os/chromiumos-design-docs/
 // system-notifications for the reasoning.
 
 // |kAlwaysShownSystemNotifierIds| is the list of system notification sources
 // which can appear regardless of the situation, such like login screen or lock
 // screen.
 const char* kAlwaysShownSystemNotifierIds[] = {
-    kNotifierDeprecatedAccelerator, kNotifierBattery, kNotifierDisplay,
-    kNotifierDisplayError,
+    kNotifierAccessibility, kNotifierDeprecatedAccelerator, kNotifierBattery,
+    kNotifierDisplay, kNotifierDisplayError,
 #if defined(OS_CHROMEOS)
     kNotifierNetworkError,
 #endif
     kNotifierPower,
     // Note: Order doesn't matter here, so keep this in alphabetic order, don't
     // just add your stuff at the end!
     NULL};
 
 // |kAshSystemNotifiers| is the list of normal system notification sources for
 // ash events. These notifications can be hidden in some context.
@@ skipping 20 matching lines @@
 
   for (size_t i = 0; id_list[i] != NULL; ++i) {
     if (notifier_id.id == id_list[i])
       return true;
   }
   return false;
 }
 
 }  // namespace
 
+const char kNotifierAccessibility[] = "ash.accessibility";
 const char kNotifierBattery[] = "ash.battery";
 const char kNotifierBluetooth[] = "ash.bluetooth";
 const char kNotifierDeprecatedAccelerator[] = "ash.accelerator-controller";
 const char kNotifierDisk[] = "ash.disk";
 const char kNotifierDisplay[] = "ash.display";
 const char kNotifierDisplayError[] = "ash.display.error";
 const char kNotifierDisplayResolutionChange[] = "ash.display.resolution-change";
 const char kNotifierDualRole[] = "ash.dual-role";
 const char kNotifierHats[] = "ash.hats";
 const char kNotifierLocale[] = "ash.locale";
@@ skipping 14 matching lines @@
   return MatchSystemNotifierId(notifier_id, kAlwaysShownSystemNotifierIds);
 }
 
 bool IsAshSystemNotifier(const message_center::NotifierId& notifier_id) {
   return ShouldAlwaysShowPopups(notifier_id) ||
          MatchSystemNotifierId(notifier_id, kAshSystemNotifiers);
 }
 
 }  // namespace system_notifier
 }  // namespace ash