Replace raw pointers to GC allocated objects by members in stack allocated objects.

Source/core/css/resolver/StyleResolverState.cpp

Index: Source/core/css/resolver/StyleResolverState.cpp
diff --git a/Source/core/css/resolver/StyleResolverState.cpp b/Source/core/css/resolver/StyleResolverState.cpp
index f7299230631d84a0ab562eca3f1db4c6dc1e6e5f..96fa5e1a29355c0ad4cf0f40186b875584970e8b 100644
--- a/Source/core/css/resolver/StyleResolverState.cpp
+++ b/Source/core/css/resolver/StyleResolverState.cpp
@@ -37,9 +37,9 @@ StyleResolverState::StyleResolverState(Document& document, Element* element, Ren
     , m_parentStyle(parentStyle)
     , m_applyPropertyToRegularStyle(true)
     , m_applyPropertyToVisitedLinkStyle(false)
-    , m_lineHeightValue(0)
+    , m_lineHeightValue(nullptr)
     , m_styleMap(*this, m_elementStyleResources)
-    , m_currentRule(0)
+    , m_currentRule(nullptr)
 {
     if (!parentStyle && m_elementContext.parentNode())
         m_parentStyle = m_elementContext.parentNode()->renderStyle();