exo: Use WMHelper to access ash accessibility related features.

components/exo/wm_helper.cc

 // Copyright 2016 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 "components/exo/wm_helper.h"
 
 #include "base/memory/ptr_util.h"
 
 namespace exo {
 namespace {
@@ skipping 44 matching lines @@
 }
 
 void WMHelper::AddMaximizeModeObserver(MaximizeModeObserver* observer) {
   maximize_mode_observers_.AddObserver(observer);
 }
 
 void WMHelper::RemoveMaximizeModeObserver(MaximizeModeObserver* observer) {
   maximize_mode_observers_.RemoveObserver(observer);
 }
 
+void WMHelper::AddAccessibilityObserver(AccessibilityObserver* observer) {
+  accessibility_observers_.AddObserver(observer);
+}
+
+void WMHelper::RemoveAccessibilityObserver(AccessibilityObserver* observer) {
+  accessibility_observers_.RemoveObserver(observer);
+}
+
 void WMHelper::NotifyWindowActivated(aura::Window* gained_active,
                                      aura::Window* lost_active) {
   FOR_EACH_OBSERVER(ActivationObserver, activation_observers_,
                     OnWindowActivated(gained_active, lost_active));
 }
 
 void WMHelper::NotifyWindowFocused(aura::Window* gained_focus,
                                    aura::Window* lost_focus) {
   FOR_EACH_OBSERVER(FocusObserver, focus_observers_,
                     OnWindowFocused(gained_focus, lost_focus));
@@ skipping 12 matching lines @@
 void WMHelper::NotifyMaximizeModeStarted() {
   FOR_EACH_OBSERVER(MaximizeModeObserver, maximize_mode_observers_,
                     OnMaximizeModeStarted());
 }
 
 void WMHelper::NotifyMaximizeModeEnded() {
   FOR_EACH_OBSERVER(MaximizeModeObserver, maximize_mode_observers_,
                     OnMaximizeModeEnded());
 }
 
+void WMHelper::NotifyAccessibilityModeChanged() {
+  FOR_EACH_OBSERVER(AccessibilityObserver, accessibility_observers_,
+                    OnAccessibilityModeChanged());
+}
+
 }  // namespace exo