Disable style sharing outside tests.

third_party/WebKit/Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc.
  * All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
@@ skipping 4214 matching lines @@
 
 void Element::AddPropertyToPresentationAttributeStyle(
     MutableStylePropertySet* style,
     CSSPropertyID property_id,
     const CSSValue* value) {
   DCHECK(IsStyledElement());
   style->SetProperty(property_id, *value);
 }
 
 bool Element::SupportsStyleSharing() const {
+  if (!RuntimeEnabledFeatures::styleSharingEnabled())
+    return false;
   if (!IsStyledElement() || !ParentOrShadowHostElement())
     return false;
   // If the element has inline style it is probably unique.
   if (InlineStyle())
     return false;
   if (IsSVGElement() && ToSVGElement(this)->AnimatedSMILStyleProperties())
     return false;
   // Ids stop style sharing if they show up in the stylesheets.
   if (HasID() &&
       GetDocument().GetStyleEngine().HasRulesForId(IdForStyleResolution()))
@@ skipping 92 matching lines @@
 }
 
 DEFINE_TRACE_WRAPPERS(Element) {
   if (HasRareData()) {
     visitor->TraceWrappers(GetElementRareData());
   }
   ContainerNode::TraceWrappers(visitor);
 }
 
 }  // namespace blink