Improve RAII of StyleResolverState.

Source/core/css/resolver/ElementResolveContext.cpp

Index: Source/core/css/resolver/ElementResolveContext.cpp
diff --git a/Source/core/css/resolver/ElementResolveContext.cpp b/Source/core/css/resolver/ElementResolveContext.cpp
index 40008283689d0ecd3035fb2dba264d1b7621c678..f79dc6fff68f8360fcde56d94b594dcb1a93593f 100644
--- a/Source/core/css/resolver/ElementResolveContext.cpp
+++ b/Source/core/css/resolver/ElementResolveContext.cpp
@@ -22,37 +22,42 @@
 #include "config.h"
 #include "core/css/resolver/ElementResolveContext.h"
 
+#include "core/animation/ActiveAnimations.h"
 #include "core/dom/Node.h"
 #include "core/dom/NodeRenderStyle.h"
 #include "core/dom/NodeRenderingTraversal.h"
 #include "core/dom/VisitedLinkState.h"
+#include "core/rendering/style/RenderStyle.h"
 
 namespace blink {
 
-ElementResolveContext::ElementResolveContext(const Document& document)
-    : m_element(nullptr)
-    , m_parentNode(nullptr)
-    , m_rootElementStyle(document.documentElement() ? document.documentElement()->renderStyle() : document.renderStyle())
-    , m_elementLinkState(NotInsideLink)
-    , m_distributedToInsertionPoint(false)
+static RenderStyle* findRootElementStyle(const Document& document, Element* element)
 {
+    Node* documentElement = document.documentElement();
+    if (documentElement && element != documentElement && documentElement->renderStyle())
+        return documentElement->renderStyle();
+    return document.renderStyle();
 }
 
-ElementResolveContext::ElementResolveContext(Element& element)
-    : m_element(&element)
-    , m_elementLinkState(element.document().visitedLinkState().determineLinkState(element))
+ElementResolveContext::ElementResolveContext(Document& document, Element* element, RenderStyle* parentStyle)
+    : m_document(document)
+    , m_element(element)
+    , m_parentNode(nullptr)
+    , m_parentStyle(parentStyle)
+    , m_activeAnimations(element ? element->activeAnimations() : nullptr)
+    , m_baseRenderStyle(m_activeAnimations ? m_activeAnimations->baseRenderStyle() : nullptr)
+    , m_rootElementStyle(findRootElementStyle(document, element))
+    , m_elementLinkState(element ? document.visitedLinkState().determineLinkState(*element) : NotInsideLink)
     , m_distributedToInsertionPoint(false)
 {
-    NodeRenderingTraversal::ParentDetails parentDetails;
-    m_parentNode = NodeRenderingTraversal::parent(&element, &parentDetails);
-    m_distributedToInsertionPoint = parentDetails.insertionPoint();
+    if (element) {
+        NodeRenderingTraversal::ParentDetails parentDetails;
+        m_parentNode = NodeRenderingTraversal::parent(element, &parentDetails);
+        m_distributedToInsertionPoint = parentDetails.insertionPoint();
 
-    const Document& document = element.document();
-    Node* documentElement = document.documentElement();
-    RenderStyle* documentStyle = document.renderStyle();
-    m_rootElementStyle = documentElement && element != documentElement ? documentElement->renderStyle() : documentStyle;
-    if (!m_rootElementStyle)
-        m_rootElementStyle = documentStyle;
+        if (!m_parentStyle && m_parentNode)
+            m_parentStyle = m_parentNode->renderStyle();
+    }
 }
 
 } // namespace blink