Add a11y on-screen keyboard to accessibility menu on system tray.

ash/default_accessibility_delegate.cc

Index: ash/default_accessibility_delegate.cc
diff --git a/ash/default_accessibility_delegate.cc b/ash/default_accessibility_delegate.cc
index 94a3d3012272f65a1f403437db0766bd5a12d506..975c3b6cc856cb0670e92ea1972dec68c259a660 100644
--- a/ash/default_accessibility_delegate.cc
+++ b/ash/default_accessibility_delegate.cc
@@ -16,6 +16,7 @@ DefaultAccessibilityDelegate::DefaultAccessibilityDelegate()
       screen_magnifier_type_(kDefaultMagnifierType),
       large_cursor_enabled_(false),
       autoclick_enabled_(false),
+      virtual_keyboard_enabled_(false),
       accessibility_alert_(A11Y_ALERT_NONE) {
 }
 
@@ -65,8 +66,12 @@ bool DefaultAccessibilityDelegate::IsAutoclickEnabled() const {
   return autoclick_enabled_;
 }
 
+void DefaultAccessibilityDelegate::SetVirtualKeyboardEnabled(bool enabled) {
+  virtual_keyboard_enabled_ = enabled;
+}
+
 bool DefaultAccessibilityDelegate::IsVirtualKeyboardEnabled() const {
-  return false;
+  return virtual_keyboard_enabled_;
 }
 
 bool DefaultAccessibilityDelegate::ShouldShowAccessibilityMenu() const {
@@ -74,7 +79,8 @@ bool DefaultAccessibilityDelegate::ShouldShowAccessibilityMenu() const {
          high_contrast_enabled_ ||
          screen_magnifier_enabled_ ||
          large_cursor_enabled_ ||
-         autoclick_enabled_;
+         autoclick_enabled_ ||
+         virtual_keyboard_enabled_;
 }
 
 void DefaultAccessibilityDelegate::SilenceSpokenFeedback() const {