Improve RAII of StyleResolverState.

Source/core/css/resolver/StyleResolverState.h

Index: Source/core/css/resolver/StyleResolverState.h
diff --git a/Source/core/css/resolver/StyleResolverState.h b/Source/core/css/resolver/StyleResolverState.h
index 10b02d855fcb197cb62e8f8ed6a98e1fa566cd5a..08e6acc161ba0287a2041331b781fc31b3bf45ef 100644
--- a/Source/core/css/resolver/StyleResolverState.h
+++ b/Source/core/css/resolver/StyleResolverState.h
@@ -45,13 +45,14 @@ class StyleResolverState {
     STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(StyleResolverState);
 public:
-    StyleResolverState(Document&, Element*, RenderStyle* parentStyle = 0);
+    StyleResolverState(const ElementResolveContext&);
+    StyleResolverState(Document&, Element*, PassRefPtr<RenderStyle>, RenderStyle* parentStyle = nullptr);
     ~StyleResolverState();
 
-    // In FontFaceSet and CanvasRenderingContext2D, we don't have an element to grab the document from.
-    // This is why we have to store the document separately.
-    Document& document() const { return *m_document; }
+    static PassRefPtr<RenderStyle> defaultStyleForElement(Document&);
+
     // These are all just pass-through methods to ElementResolveContext.
+    Document& document() const { return m_elementContext.document(); }
     Element* element() const { return m_elementContext.element(); }
     const ContainerNode* parentNode() const { return m_elementContext.parentNode(); }
     const RenderStyle* rootElementStyle() const { return m_elementContext.rootElementStyle(); }
@@ -60,12 +61,6 @@ public:
 
     const ElementResolveContext& elementContext() const { return m_elementContext; }
 
-    void setStyle(PassRefPtr<RenderStyle> style)
-    {
-        m_style = style;
-        m_cssToLengthConversionData.setStyle(m_style.get());
-        m_fontBuilder.setStyle(m_style.get());
-    }
     const RenderStyle* style() const { return m_style.get(); }
     RenderStyle* style() { return m_style.get(); }
     PassRefPtr<RenderStyle> takeStyle() { return m_style.release(); }
@@ -76,7 +71,6 @@ public:
     const CSSAnimationUpdate* animationUpdate() { return m_animationUpdate.get(); }
     PassOwnPtrWillBeRawPtr<CSSAnimationUpdate> takeAnimationUpdate();
 
-    void setParentStyle(PassRefPtr<RenderStyle> parentStyle) { m_parentStyle = parentStyle; }
     const RenderStyle* parentStyle() const { return m_parentStyle.get(); }
     RenderStyle* parentStyle() { return m_parentStyle.get(); }
 
@@ -93,9 +87,6 @@ public:
     // Holds all attribute names found while applying "content" properties that contain an "attr()" value.
     Vector<AtomicString>& contentAttrValues() { return m_contentAttrValues; }
 
-    void setLineHeightValue(CSSValue* value) { m_lineHeightValue = value; }
-    CSSValue* lineHeightValue() { return m_lineHeightValue; }
-
     void cacheUserAgentBorderAndBackground()
     {
         // RenderTheme only needs the cached style if it has an appearance,
@@ -137,7 +128,6 @@ public:
 
 private:
     ElementResolveContext m_elementContext;
-    RawPtrWillBeMember<Document> m_document;
 
     // m_style is the primary output for each element's style resolve.
     RefPtr<RenderStyle> m_style;
@@ -153,8 +143,6 @@ private:
     bool m_applyPropertyToRegularStyle;
     bool m_applyPropertyToVisitedLinkStyle;
 
-    RawPtrWillBeMember<CSSValue> m_lineHeightValue;
-
     FontBuilder m_fontBuilder;
 
     OwnPtr<CachedUAStyle> m_cachedUAStyle;