Cleans up gyp file for views example and removes duplicate code

ui/views/controls/tabbed_pane/tabbed_pane_listener.h

Index: ui/views/controls/tabbed_pane/tabbed_pane_listener.h
diff --git a/ui/views/controls/tabbed_pane/tabbed_pane_listener.h b/ui/views/controls/tabbed_pane/tabbed_pane_listener.h
index d2607889ef1b5b6b79f47899485aebb3dd583e12..83376f79df063d2dc8ec1817f9dcfa877453794f 100644
--- a/ui/views/controls/tabbed_pane/tabbed_pane_listener.h
+++ b/ui/views/controls/tabbed_pane/tabbed_pane_listener.h
@@ -5,11 +5,13 @@
 #ifndef UI_VIEWS_CONTROLS_TABBED_PANE_TABBED_PANE_LISTENER_H_
 #define UI_VIEWS_CONTROLS_TABBED_PANE_TABBED_PANE_LISTENER_H_
 
+#include "ui/views/views_export.h"
+
 namespace views {
 
 // An interface implemented by an object to let it know that a tabbed pane was
 // selected by the user at the specified index.
-class TabbedPaneListener {
+class VIEWS_EXPORT TabbedPaneListener {
  public:
   // Called when the tab at |index| is selected by the user.
   virtual void TabSelectedAt(int index) = 0;