Fixing caps lock problems under ChromeOS where the tray does not properly follow the real caps lock…

chromeos/ime/xkeyboard.h

 // 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.
 
 #ifndef CHROMEOS_IME_XKEYBOARD_H_
 #define CHROMEOS_IME_XKEYBOARD_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 18 matching lines @@
   kEscapeKey,
   // IMPORTANT: You should update kCustomizableKeys[] in .cc file, if you
   // add a customizable key.
   kNumModifierKeys,
 };
 
 class InputMethodUtil;
 
 class CHROMEOS_EXPORT XKeyboard {
  public:
+  class Observer {
+   public:
+    // Called when the caps lock state has changed.
+    virtual void OnCapsLockChanged(bool enabled) = 0;
+  };
+
   virtual ~XKeyboard() {}
 
+  // Adds/removes observer.
+  virtual void AddObserver(Observer* observer) = 0;
+  virtual void RemoveObserver(Observer* observer) = 0;
+
   // Sets the current keyboard layout to |layout_name|. This function does not
   // change the current mapping of the modifier keys. Returns true on success.
   virtual bool SetCurrentKeyboardLayoutByName(
       const std::string& layout_name) = 0;
 
   // Sets the current keyboard layout again. We have to call the function every
   // time when "XI_HierarchyChanged" XInput2 event is sent to Chrome. See
   // xinput_hierarchy_changed_event_listener.h for details.
   virtual bool ReapplyCurrentKeyboardLayout() = 0;
 
@@ skipping 49 matching lines @@
 
   // Note: At this moment, classes other than InputMethodManager should not
   // instantiate the XKeyboard class.
   static XKeyboard* Create();
 };
 
 }  // namespace input_method
 }  // namespace chromeos
 
 #endif  // CHROMEOS_IME_XKEYBOARD_H_