Perf bots for https://codereview.chromium.org/2473743003

third_party/WebKit/Source/core/css/resolver/SharedStyleFinder.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc.
  * All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
@@ skipping 41 matching lines @@
 #include "core/style/ComputedStyle.h"
 #include "core/svg/SVGElement.h"
 #include "platform/instrumentation/tracing/TraceEvent.h"
 #include "wtf/HashSet.h"
 #include "wtf/text/AtomicString.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
+inline ComputedStyle* getElementStyle(Element& element) {
+  if (element.needsReattachLayoutTree()) {
+    StyleReattachData styleReattachData =
+        element.document().getStyleReattachData(element);
+    if (styleReattachData.computedStyle)
+      return styleReattachData.computedStyle.get();
+  }
+  return element.mutableComputedStyle();
+}
+
 bool SharedStyleFinder::canShareStyleWithControl(Element& candidate) const {
   if (!isHTMLInputElement(candidate) || !isHTMLInputElement(element()))
     return false;
 
   HTMLInputElement& candidateInput = toHTMLInputElement(candidate);
   HTMLInputElement& thisInput = toHTMLInputElement(element());
 
   if (candidateInput.isAutofilled() != thisInput.isAutofilled())
     return false;
   if (candidateInput.shouldAppearChecked() != thisInput.shouldAppearChecked())
@@ skipping 149 matching lines @@
       return false;
   }
   return true;
 }
 
 DISABLE_CFI_PERF
 bool SharedStyleFinder::canShareStyleWithElement(Element& candidate) const {
   if (element() == candidate)
     return false;
   Element* parent = candidate.parentOrShadowHostElement();
-  const ComputedStyle* style = candidate.computedStyle();
+  const ComputedStyle* style = getElementStyle(candidate);
   if (!style)
     return false;
   if (!style->isSharable())
     return false;
   if (!parent)
     return false;
-  if (element().parentOrShadowHostElement()->computedStyle() !=
-      parent->computedStyle())
+  if (getElementStyle(*element().parentOrShadowHostElement()) !=
+      getElementStyle(*parent))
     return false;
   if (candidate.tagQName() != element().tagQName())
     return false;
   if (candidate.inlineStyle())
     return false;
   if (candidate.needsStyleRecalc())
     return false;
   if (candidate.isSVGElement() &&
       toSVGElement(candidate).animatedSMILStyleProperties())
     return false;
@@ skipping 150 matching lines @@
   }
 
   // Tracking child index requires unique style for each node. This may get set
   // by the sibling rule match above.
   if (!element().parentElementOrShadowRoot()->childrenSupportStyleSharing()) {
     INCREMENT_STYLE_STATS_COUNTER(document().styleEngine(),
                                   sharedStyleRejectedByParent, 1);
     return nullptr;
   }
 
-  return shareElement->mutableComputedStyle();
+  return getElementStyle(*shareElement);
 }
 
 }  // namespace blink