Update StickyKeys overlay to show or hide AltGr depending on the

chromeos/ime/xkeyboard.h

Index: chromeos/ime/xkeyboard.h
diff --git a/chromeos/ime/xkeyboard.h b/chromeos/ime/xkeyboard.h
index eae5e7c5c1b0d5b506e7b70c902552449119f38a..b07e4f44ba3d8c4043f0872e2ab06b3021de4a2f 100644
--- a/chromeos/ime/xkeyboard.h
+++ b/chromeos/ime/xkeyboard.h
@@ -70,6 +70,12 @@ class CHROMEOS_EXPORT XKeyboard {
   // threads.
   virtual bool CapsLockIsEnabled() = 0;
 
+  // Returns true if the current layout supports ISO Level 5 shift.
+  virtual bool IsISOLevel5ShiftAvailable() const = 0;
+
+  // Returns true if the current layout supports alt gr.
+  virtual bool IsAltGrAvailable() const = 0;
+
   // Turns on and off the auto-repeat of the keyboard. Returns true on success.
   // Do not call the function from non-UI threads.
   virtual bool SetAutoRepeatEnabled(bool enabled) = 0;