Do not suppress referrers for '<a ... rel="noopener">'.

third_party/WebKit/Source/core/loader/EmptyClients.h

 /*
  * Copyright (C) 2006 Eric Seidel (eric@webkit.org)
  * Copyright (C) 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 2012 Samsung Electronics. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 66 matching lines @@
     IntRect windowRect() override { return IntRect(); }
 
     IntRect pageRect() override { return IntRect(); }
 
     void focus() override {}
 
     bool canTakeFocus(WebFocusType) override { return false; }
     void takeFocus(WebFocusType) override {}
 
     void focusedNodeChanged(Node*, Node*) override {}
-    Page* createWindow(LocalFrame*, const FrameLoadRequest&, const WindowFeatures&, NavigationPolicy, ShouldSetOpener) override { return nullptr; }
+    Page* createWindow(LocalFrame*, const FrameLoadRequest&, const WindowFeatures&, NavigationPolicy) override { return nullptr; }
     void show(NavigationPolicy) override {}
 
     void didOverscroll(const FloatSize&, const FloatSize&, const FloatPoint&, const FloatSize&) override {}
 
     void beginLifecycleUpdates() override { }
 
     bool hadFormInteraction() const override { return false; }
 
     void startDragging(LocalFrame*, const WebDragData&, WebDragOperationsMask, const WebImage& dragImage, const WebPoint& dragImageOffset) {}
     bool acceptsLoadDrops() const override { return true; }
@@ skipping 228 matching lines @@
     ~EmptyContextMenuClient() override {}
     void showContextMenu(const ContextMenu*) override {}
     void clearContextMenu() override {}
 };
 
 CORE_EXPORT void fillWithEmptyClients(Page::PageClients&);
 
 } // namespace blink
 
 #endif // EmptyClients_h