Update Windows UI on system color changes.

chrome/browser/ui/libgtk2ui/gtk2_ui.h

Index: chrome/browser/ui/libgtk2ui/gtk2_ui.h
diff --git a/chrome/browser/ui/libgtk2ui/gtk2_ui.h b/chrome/browser/ui/libgtk2ui/gtk2_ui.h
index c27bcc5314436e55803a28221f5fbed5974fdd55..85abf3039025f6070d070894ee8e81bc992151f6 100644
--- a/chrome/browser/ui/libgtk2ui/gtk2_ui.h
+++ b/chrome/browser/ui/libgtk2ui/gtk2_ui.h
@@ -107,10 +107,6 @@ class Gtk2UI : public views::LinuxUI {
       views::WindowButtonOrderObserver* observer) OVERRIDE;
   virtual void RemoveWindowButtonOrderObserver(
       views::WindowButtonOrderObserver* observer) OVERRIDE;
-  virtual void AddNativeThemeChangeObserver(
-      views::NativeThemeChangeObserver* observer) OVERRIDE;
-  virtual void RemoveNativeThemeChangeObserver(
-      views::NativeThemeChangeObserver* observer) OVERRIDE;
   virtual bool UnityIsRunning() OVERRIDE;
   virtual NonClientMiddleClickAction GetNonClientMiddleClickAction() OVERRIDE;
   virtual void NotifyWindowManagerStartupComplete() OVERRIDE;
@@ -246,9 +242,6 @@ class Gtk2UI : public views::LinuxUI {
   // Objects to notify when the window frame button order changes.
   ObserverList<views::WindowButtonOrderObserver> observer_list_;
 
-  // Observers to notify when the theme state changes.
-  ObserverList<views::NativeThemeChangeObserver> theme_change_observers_;
-
   // Whether we should lower the window on a middle click to the non client
   // area.
   NonClientMiddleClickAction middle_click_action_;