Oilpan: Replace Node* pointers with Member<Node>s

- Make SelectorCheckerContext STACK_ALLOCATED.
- Make FocusCandidate STACK_ALLOCATED.
- Make TreeBoundaryCrossingRuleSetMap a hash map from Member<Node> to Member<CSSStyleSheetRuleSubSet>. This hash map doesn't need to be weak.

BUG=340522

Review URL: https://codereview.chromium.org/423953003

git-svn-id: svn://svn.chromium.org/blink/trunk@179087 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/css/SelectorChecker.cpp

@@ -934,7 +934,7 @@ bool SelectorChecker::checkOne(const SelectorCheckingContext& context, const Sib
                             break;
                         }
                         hostContext.contextFlags = DefaultBehavior;
-                        hostContext.scope = 0;
+                        hostContext.scope = nullptr;
 
                         if (selector.pseudoType() == CSSSelector::PseudoHost)
                             break;

third_party/WebKit/Source/core/css/SelectorChecker.h

@@ -55,12 +55,14 @@ public:
     };
 
     struct SelectorCheckingContext {
+        STACK_ALLOCATED();
+    public:
         // Initial selector constructor
         SelectorCheckingContext(const CSSSelector& selector, Element* element, VisitedMatchType visitedMatchType)
             : selector(&selector)
             , element(element)
-            , previousElement(0)
-            , scope(0)
+            , previousElement(nullptr)
+            , scope(nullptr)
             , visitedMatchType(visitedMatchType)
             , pseudoId(NOPSEUDO)
             , elementStyle(0)
@@ -71,12 +73,13 @@ public:
             , hasSelectionPseudo(false)
             , isUARule(false)
             , contextFlags(DefaultBehavior)
-        { }
+        {
+        }
 
         const CSSSelector* selector;
-        Element* element;
-        Element* previousElement;
-        const ContainerNode* scope;
+        RawPtrWillBeMember<Element> element;
+        RawPtrWillBeMember<Element> previousElement;
+        RawPtrWillBeMember<const ContainerNode> scope;
         VisitedMatchType visitedMatchType;
         PseudoId pseudoId;
         RenderStyle* elementStyle;

third_party/WebKit/Source/core/css/TreeBoundaryCrossingRules.h

@@ -54,7 +54,7 @@ private:
     void collectFeaturesFromRuleSubSet(CSSStyleSheetRuleSubSet*, RuleFeatureSet&);
 
     DocumentOrderedList m_scopingNodes;
-    typedef WillBeHeapHashMap<const ContainerNode*, OwnPtrWillBeMember<CSSStyleSheetRuleSubSet> > TreeBoundaryCrossingRuleSetMap;
+    typedef WillBeHeapHashMap<RawPtrWillBeMember<const ContainerNode>, OwnPtrWillBeMember<CSSStyleSheetRuleSubSet> > TreeBoundaryCrossingRuleSetMap;
     TreeBoundaryCrossingRuleSetMap m_treeBoundaryCrossingRuleSetMap;
 };
 

third_party/WebKit/Source/core/page/SpatialNavigation.cpp

@@ -55,9 +55,9 @@ static LayoutRect rectToAbsoluteCoordinates(LocalFrame* initialFrame, const Layo
 static bool isScrollableNode(const Node*);
 
 FocusCandidate::FocusCandidate(Node* node, FocusType type)
-    : visibleNode(0)
-    , focusableNode(0)
-    , enclosingScrollableBox(0)
+    : visibleNode(nullptr)
+    , focusableNode(nullptr)
+    , enclosingScrollableBox(nullptr)
     , distance(maxDistance())
     , alignment(None)
     , isOffscreen(true)

third_party/WebKit/Source/core/page/SpatialNavigation.h

@@ -98,10 +98,12 @@ enum RectsAlignment {
 };
 
 struct FocusCandidate {
+    STACK_ALLOCATED();
+public:
     FocusCandidate()
-        : visibleNode(0)
-        , focusableNode(0)
-        , enclosingScrollableBox(0)
+        : visibleNode(nullptr)
+        , focusableNode(nullptr)
+        , enclosingScrollableBox(nullptr)
         , distance(maxDistance())
         , alignment(None)
         , isOffscreen(true)
@@ -119,9 +121,9 @@ struct FocusCandidate {
     // We handle differently visibleNode and FocusableNode to properly handle the areas of imagemaps,
     // where visibleNode would represent the image element and focusableNode would represent the area element.
     // In all other cases, visibleNode and focusableNode are one and the same.
-    Node* visibleNode;
-    Node* focusableNode;
-    Node* enclosingScrollableBox;
+    RawPtrWillBeMember<Node> visibleNode;
+    RawPtrWillBeMember<Node> focusableNode;
+    RawPtrWillBeMember<Node> enclosingScrollableBox;
     long long distance;
     RectsAlignment alignment;
     LayoutRect rect;