Have Element::ensureMutableInlineStyle() return a reference

Source/core/css/PageRuleCollector.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/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 63 matching lines @@
 
     rules->compactRulesIfNeeded();
     WillBeHeapVector<RawPtrWillBeMember<StyleRulePage> > matchedPageRules;
     matchPageRulesForList(matchedPageRules, rules->pageRules(), m_isLeftPage, m_isFirstPage, m_pageName);
     if (matchedPageRules.isEmpty())
         return;
 
     std::stable_sort(matchedPageRules.begin(), matchedPageRules.end(), comparePageRules);
 
     for (unsigned i = 0; i < matchedPageRules.size(); i++)
-        m_result.addMatchedProperties(matchedPageRules[i]->properties());
+        m_result.addMatchedProperties(&matchedPageRules[i]->properties());
 }
 
 static bool checkPageSelectorComponents(const CSSSelector* selector, bool isLeftPage, bool isFirstPage, const String& pageName)
 {
     for (const CSSSelector* component = selector; component; component = component->tagHistory()) {
         if (component->m_match == CSSSelector::Tag) {
             const AtomicString& localName = component->tagQName().localName();
             if (localName != starAtom && localName != pageName)
                 return false;
         }
@@ skipping 11 matching lines @@
 
 void PageRuleCollector::matchPageRulesForList(WillBeHeapVector<RawPtrWillBeMember<StyleRulePage> >& matchedRules, const WillBeHeapVector<RawPtrWillBeMember<StyleRulePage> >& rules, bool isLeftPage, bool isFirstPage, const String& pageName)
 {
     for (unsigned i = 0; i < rules.size(); ++i) {
         StyleRulePage* rule = rules[i];
 
         if (!checkPageSelectorComponents(rule->selector(), isLeftPage, isFirstPage, pageName))
             continue;
 
         // If the rule has no properties to apply, then ignore it.
-        const StylePropertySet* properties = rule->properties();
-        if (!properties || properties->isEmpty())
+        const StylePropertySet& properties = rule->properties();
+        if (properties.isEmpty())
             continue;
 
         // Add this rule to our list of matched rules.
         matchedRules.append(rule);
     }
 }
 
 } // namespace WebCore