Add unit tests for screen capture and share notification UI.

ash/system/chromeos/screen_security/screen_share_tray_item.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 ASH_SYSTEM_CHROMEOS_SCREEN_SHARE_SCREEN_SHARE_TRAY_ITEM_H_
 #define ASH_SYSTEM_CHROMEOS_SCREEN_SHARE_SCREEN_SHARE_TRAY_ITEM_H_
 
 #include "ash/system/chromeos/screen_security/screen_share_observer.h"
 #include "ash/system/chromeos/screen_security/screen_tray_item.h"
 
 namespace views {
 class View;
 }
 
 namespace ash {
 namespace internal {
 
-class ScreenShareTrayItem : public ScreenTrayItem,
-                            public ScreenShareObserver {
+class ASH_EXPORT ScreenShareTrayItem : public ScreenTrayItem,
+                                       public ScreenShareObserver {
  public:
   explicit ScreenShareTrayItem(SystemTray* system_tray);
   virtual ~ScreenShareTrayItem();
 
  private:
   // Overridden from SystemTrayItem.
   virtual views::View* CreateTrayView(user::LoginStatus status) OVERRIDE;
   virtual views::View* CreateDefaultView(user::LoginStatus status) OVERRIDE;
   virtual views::View* CreateNotificationView(
       user::LoginStatus status) OVERRIDE;
 
   // Overridden from ScreenShareObserver.
   virtual void OnScreenShareStart(
       const base::Closure& stop_callback,
       const base::string16& helper_name) OVERRIDE;
   virtual void OnScreenShareStop() OVERRIDE;
 
   base::string16 helper_name_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenShareTrayItem);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CHROMEOS_SCREEN_SHARE_SCREEN_SHARE_TRAY_ITEM_H_