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

chromeos/ime/xkeyboard.h

Index: chromeos/ime/xkeyboard.h
diff --git a/chromeos/ime/xkeyboard.h b/chromeos/ime/xkeyboard.h
index b07e4f44ba3d8c4043f0872e2ab06b3021de4a2f..199338f78196a8316390b75fa7f7ceaaf9368217 100644
--- a/chromeos/ime/xkeyboard.h
+++ b/chromeos/ime/xkeyboard.h
@@ -36,8 +36,18 @@ class InputMethodUtil;
 
 class CHROMEOS_EXPORT XKeyboard {
  public:
+  class Observer {
+   public:
+    // Called when the caps lock state has changed.
+    virtual void OnCapsLockChanged() = 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(