Stash ComputedStyles on new HeapHashMap on Document.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 1228 matching lines @@
 
       return body;
     }
 
     return documentElement();
   }
 
   return body();
 }
 
+// We use HashMap::set over HashMap::add here as we want to
+// replace the ComputedStyle but not the Element if the Element is
+// already present.
+void Document::addNonAttachedStyle(Element& element,
+                                   RefPtr<ComputedStyle> computedStyle) {
+  m_nonAttachedStyle.set(&element, computedStyle);
+}
+
+ComputedStyle* Document::getNonAttachedStyle(Element& element) {
+  RefPtr<ComputedStyle> style = m_nonAttachedStyle.get(&element);
+  return style.get();
+}
+
 /*
  * Performs three operations:
  *  1. Convert control characters to spaces
  *  2. Trim leading and trailing spaces
  *  3. Collapse internal whitespace.
  */
 template <typename CharacterType>
 static inline String canonicalizedTitle(Document* document,
                                         const String& title) {
   unsigned length = title.length();
@@ skipping 651 matching lines @@
     inheritHtmlAndBodyElementStyles(change);
     dirtyElementsForLayerUpdate();
     if (documentElement->shouldCallRecalcStyle(change))
       documentElement->recalcStyle(change);
     while (dirtyElementsForLayerUpdate())
       documentElement->recalcStyle(NoChange);
   }
 
   view()->recalcOverflowAfterStyleChange();
 
+  // Only retain the HashMap for the duration of StyleRecalc and
+  // LayoutTreeConstruction.
+  m_nonAttachedStyle.clear();
   clearChildNeedsStyleRecalc();
 
   resolver.clearStyleSharingList();
 
   m_wasPrinting = m_printing;
 
   DCHECK(!needsStyleRecalc());
   DCHECK(!childNeedsStyleRecalc());
   DCHECK(inStyleRecalc());
   DCHECK_EQ(styleResolver(), &resolver);
+  DCHECK(m_nonAttachedStyle.isEmpty());
   m_lifecycle.advanceTo(DocumentLifecycle::StyleClean);
   if (shouldRecordStats) {
     TRACE_EVENT_END2("blink,blink_style", "Document::updateStyle",
                      "resolverAccessCount",
                      styleEngine().styleForElementCount() - initialElementCount,
                      "counters", styleEngine().stats()->toTracedValue());
   } else {
     TRACE_EVENT_END1(
         "blink,blink_style", "Document::updateStyle", "resolverAccessCount",
         styleEngine().styleForElementCount() - initialElementCount);
@@ skipping 4379 matching lines @@
   visitor->trace(m_svgExtensions);
   visitor->trace(m_timeline);
   visitor->trace(m_compositorPendingAnimations);
   visitor->trace(m_contextDocument);
   visitor->trace(m_canvasFontCache);
   visitor->trace(m_intersectionObserverController);
   visitor->trace(m_intersectionObserverData);
   visitor->trace(m_snapCoordinator);
   visitor->trace(m_resizeObserverController);
   visitor->trace(m_propertyRegistry);
+  visitor->trace(m_nonAttachedStyle);
   Supplementable<Document>::trace(visitor);
   TreeScope::trace(visitor);
   ContainerNode::trace(visitor);
   ExecutionContext::trace(visitor);
   SecurityContext::trace(visitor);
 }
 
 void Document::onVisibilityMaybeChanged(bool visible) {
   DCHECK(frame());
   if (visible && !m_visibilityWasLogged && frame()->isCrossOriginSubframe()) {
@@ skipping 30 matching lines @@
 }
 
 void showLiveDocumentInstances() {
   WeakDocumentSet& set = liveDocumentSet();
   fprintf(stderr, "There are %u documents currently alive:\n", set.size());
   for (Document* document : set)
     fprintf(stderr, "- Document %p URL: %s\n", document,
             document->url().getString().utf8().data());
 }
 #endif