Make stylesheet owner node a reference instead of pointer.

third_party/WebKit/Source/core/html/HTMLLinkElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Rob Buis (rwlbuis@gmail.com)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 187 matching lines @@
     if (!insertionPoint->isConnected())
         return InsertionDone;
     DCHECK(isConnected());
     if (!shouldLoadLink()) {
         DCHECK(isInShadowTree());
         String message = "HTML element <link> is ignored in shadow tree.";
         document().addConsoleMessage(ConsoleMessage::create(JSMessageSource, WarningMessageLevel, message));
         return InsertionDone;
     }
 
-    document().styleEngine().addStyleSheetCandidateNode(this);
+    document().styleEngine().addStyleSheetCandidateNode(*this);
 
     process();
 
     if (m_link)
         m_link->ownerInserted();
 
     return InsertionDone;
 }
 
 void HTMLLinkElement::removedFrom(ContainerNode* insertionPoint)
 {
     // Store the result of isConnected() here before Node::removedFrom(..) clears the flags.
     bool wasConnected = isConnected();
     HTMLElement::removedFrom(insertionPoint);
     if (!insertionPoint->isConnected())
         return;
 
     m_linkLoader->released();
 
     if (!wasConnected) {
         DCHECK(!linkStyle() || !linkStyle()->hasSheet());
         return;
     }
-    document().styleEngine().removeStyleSheetCandidateNode(this);
+    document().styleEngine().removeStyleSheetCandidateNode(*this);
 
     StyleSheet* removedSheet = sheet();
 
     if (m_link)
         m_link->ownerRemoved();
 
     document().styleEngine().setNeedsActiveStyleUpdate(removedSheet, FullStyleUpdate);
 }
 
 void HTMLLinkElement::finishParsingChildren()
@@ skipping 209 matching lines @@
 
     DEFINE_STATIC_LOCAL(EnumerationHistogram, restoredCachedStyleSheetHistogram, ("Blink.RestoredCachedStyleSheet", 2));
     DEFINE_STATIC_LOCAL(EnumerationHistogram, restoredCachedStyleSheet2Histogram, ("Blink.RestoredCachedStyleSheet2", StyleSheetCacheStatusCount));
 
     if (StyleSheetContents* restoredSheet = const_cast<CSSStyleSheetResource*>(cachedStyleSheet)->restoreParsedStyleSheet(parserContext)) {
         DCHECK(restoredSheet->isCacheableForResource());
         DCHECK(!restoredSheet->isLoading());
 
         if (m_sheet)
             clearSheet();
-        m_sheet = CSSStyleSheet::create(restoredSheet, m_owner);
+        m_sheet = CSSStyleSheet::create(restoredSheet, *m_owner);
         m_sheet->setMediaQueries(MediaQuerySet::create(m_owner->media()));
         if (m_owner->isInDocumentTree())
             setSheetTitle(m_owner->title());
         setCrossOriginStylesheetStatus(m_sheet.get());
 
         m_loading = false;
         restoredSheet->checkLoaded();
 
         restoredCachedStyleSheetHistogram.count(true);
         restoredCachedStyleSheet2Histogram.count(StyleSheetInMemoryCache);
         return;
     }
     restoredCachedStyleSheetHistogram.count(false);
     StyleSheetCacheStatus cacheStatus = cachedStyleSheet->response().wasCached() ? StyleSheetInDiskCache : StyleSheetNewEntry;
     restoredCachedStyleSheet2Histogram.count(cacheStatus);
 
     StyleSheetContents* styleSheet = StyleSheetContents::create(href, parserContext);
 
     if (m_sheet)
         clearSheet();
 
-    m_sheet = CSSStyleSheet::create(styleSheet, m_owner);
+    m_sheet = CSSStyleSheet::create(styleSheet, *m_owner);
     m_sheet->setMediaQueries(MediaQuerySet::create(m_owner->media()));
     if (m_owner->isInDocumentTree())
         setSheetTitle(m_owner->title());
     setCrossOriginStylesheetStatus(m_sheet.get());
 
     styleSheet->parseAuthorStyleSheet(cachedStyleSheet, m_owner->document().getSecurityOrigin());
 
     m_loading = false;
     styleSheet->notifyLoadedSheet(cachedStyleSheet);
     styleSheet->checkLoaded();
@@ skipping 50 matching lines @@
         return;
     m_pendingSheetType = type;
 
     if (m_pendingSheetType == NonBlocking)
         return;
     m_owner->document().styleEngine().addPendingSheet(m_styleEngineContext);
 }
 
 void LinkStyle::removePendingSheet()
 {
+    DCHECK(m_owner);
     PendingSheetType type = m_pendingSheetType;
     m_pendingSheetType = None;
 
     if (type == None)
         return;
     if (type == NonBlocking) {
         // Tell StyleEngine to re-compute styleSheets of this m_owner's treescope.
-        m_owner->document().styleEngine().modifiedStyleSheetCandidateNode(m_owner);
+        m_owner->document().styleEngine().modifiedStyleSheetCandidateNode(*m_owner);
         return;
     }
 
-    m_owner->document().styleEngine().removePendingSheet(m_owner, m_styleEngineContext);
+    m_owner->document().styleEngine().removePendingSheet(*m_owner, m_styleEngineContext);
 }
 
 void LinkStyle::setDisabledState(bool disabled)
 {
     LinkStyle::DisabledState oldDisabledState = m_disabledState;
     m_disabledState = disabled ? Disabled : EnabledViaScript;
     if (oldDisabledState != m_disabledState) {
         // If we change the disabled state while the sheet is still loading, then we have to
         // perform three checks:
         if (styleSheetIsLoading()) {
@@ skipping 147 matching lines @@
 }
 
 DEFINE_TRACE(LinkStyle)
 {
     visitor->trace(m_sheet);
     LinkResource::trace(visitor);
     ResourceOwner<StyleSheetResource>::trace(visitor);
 }
 
 } // namespace blink