Add always-on-top property to app windows

chrome/browser/ui/cocoa/apps/native_app_window_cocoa.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 CHROME_BROWSER_UI_COCOA_APPS_NATIVE_APP_WINDOW_COCOA_H_
 #define CHROME_BROWSER_UI_COCOA_APPS_NATIVE_APP_WINDOW_COCOA_H_
 
 #import <Cocoa/Cocoa.h>
 #include <vector>
 
@@ skipping 119 matching lines @@
   virtual void RenderViewHostChanged(
       content::RenderViewHost* old_host,
       content::RenderViewHost* new_host) OVERRIDE;
 
   // These are used to simulate Mac-style hide/show. Since windows can be hidden
   // and shown using the app.window API, this sets is_hidden_with_app_ to
   // differentiate the reason a window was hidden.
   virtual void ShowWithApp() OVERRIDE;
   virtual void HideWithApp() OVERRIDE;
 
+  virtual void SetAlwaysOnTop(bool always_on_top) OVERRIDE;
+
   // WebContentsModalDialogHost implementation.
   virtual gfx::NativeView GetHostView() const OVERRIDE;
   virtual gfx::Point GetDialogPosition(const gfx::Size& size) OVERRIDE;
   virtual gfx::Size GetMaximumDialogSize() OVERRIDE;
   virtual void AddObserver(
       web_modal::ModalDialogHostObserver* observer) OVERRIDE;
   virtual void RemoveObserver(
       web_modal::ModalDialogHostObserver* observer) OVERRIDE;
 
  private:
@@ skipping 69 matching lines @@
   NSPoint last_mouse_location_;
 
   // The Extension Command Registry used to determine which keyboard events to
   // handle.
   scoped_ptr<ExtensionKeybindingRegistryCocoa> extension_keybinding_registry_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeAppWindowCocoa);
 };
 
 #endif  // CHROME_BROWSER_UI_COCOA_APPS_NATIVE_APP_WINDOW_COCOA_H_