Order the GL overlays above windows if possible.

content/browser/web_contents/web_contents_view_mac.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_MAC_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 
 #include <string>
@@ skipping 67 matching lines @@
                             int error_code) OVERRIDE;
   virtual void SizeContents(const gfx::Size& size) OVERRIDE;
   virtual void Focus() OVERRIDE;
   virtual void SetInitialFocus() OVERRIDE;
   virtual void StoreFocus() OVERRIDE;
   virtual void RestoreFocus() OVERRIDE;
   virtual WebDropData* GetDropData() const OVERRIDE;
   virtual bool IsEventTracking() const OVERRIDE;
   virtual void CloseTabAfterEventTracking() OVERRIDE;
   virtual gfx::Rect GetViewBounds() const OVERRIDE;
+  virtual void SetAllowOverlappingViews(bool overlapping) OVERRIDE;
 
   // Backend implementation of RenderViewHostDelegateView.
   virtual void ShowContextMenu(const ContextMenuParams& params,
                                ContextMenuSourceType type) OVERRIDE;
   virtual void ShowPopupMenu(const gfx::Rect& bounds,
                              int item_height,
                              double item_font_size,
                              int selected_item,
                              const std::vector<WebMenuItem>& items,
                              bool right_aligned,
@@ skipping 21 matching lines @@
   // The Cocoa NSView that lives in the view hierarchy.
   scoped_nsobject<WebContentsViewCocoa> cocoa_view_;
 
   // Keeps track of which NSView has focus so we can restore the focus when
   // focus returns.
   scoped_nsobject<FocusTracker> focus_tracker_;
 
   // Our optional delegate.
   scoped_ptr<WebContentsViewDelegate> delegate_;
 
+  // Whether to allow overlapping views.
+  bool allow_overlapping_views_;
+
   DISALLOW_COPY_AND_ASSIGN(WebContentsViewMac);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_MAC_H_