Fon't drop the FontSelector in LayoutThemeMac::setFontFromControlSize.

Source/core/layout/LayoutThemeMac.mm

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Google, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 581 matching lines @@
     fontDescription.setGenericFamily(FontDescription::SerifFamily);
 
     NSFont* font = [NSFont systemFontOfSize:[NSFont systemFontSizeForControlSize:controlSize]];
     fontDescription.firstFamily().setFamily([font webCoreFamilyName]);
     fontDescription.setComputedSize([font pointSize] * style.effectiveZoom());
     fontDescription.setSpecifiedSize([font pointSize] * style.effectiveZoom());
 
     // Reset line height.
     style.setLineHeight(ComputedStyle::initialLineHeight());
 
+    // TODO(esprehn): The fontSelector manual management is buggy and error prone.
+    FontSelector* fontSelector = style.font().fontSelector();
     if (style.setFontDescription(fontDescription))
-        style.font().update(nullptr);
+        style.font().update(fontSelector);
 }
 
 NSControlSize LayoutThemeMac::controlSizeForSystemFont(const ComputedStyle& style) const
 {
     float fontSize = style.fontSize();
     float zoomLevel = style.effectiveZoom();
     if (zoomLevel != 1)
         fontSize /= zoomLevel;
     if (fontSize >= [NSFont systemFontSizeForControlSize:NSRegularControlSize])
         return NSRegularControlSize;
@@ skipping 554 matching lines @@
 
 bool LayoutThemeMac::shouldUseFallbackTheme(const ComputedStyle& style) const
 {
     ControlPart part = style.appearance();
     if (part == CheckboxPart || part == RadioPart)
         return style.effectiveZoom() != 1;
     return false;
 }
 
 } // namespace blink