Refactor the Heap into ThreadHeap to prepare for per thread heaps

third_party/WebKit/Source/platform/heap/Visitor.h

Index: third_party/WebKit/Source/platform/heap/Visitor.h
diff --git a/third_party/WebKit/Source/platform/heap/Visitor.h b/third_party/WebKit/Source/platform/heap/Visitor.h
index c65907728e1f115ccd2c8b95dc6f359b79f05c7e..561e966d2777a064abd18f02559b387159c2f995 100644
--- a/third_party/WebKit/Source/platform/heap/Visitor.h
+++ b/third_party/WebKit/Source/platform/heap/Visitor.h
@@ -52,6 +52,7 @@ class InlinedGlobalMarkingVisitor;
 template<typename T> class TraceTrait;
 template<typename T> class TraceEagerlyTrait;
 class Visitor;
+class GCData;
 
 // The TraceMethodDelegate is used to convert a trace method for type T to a TraceCallback.
 // This allows us to pass a type's trace method as a parameter to the PersistentNode
@@ -121,6 +122,8 @@ public:
 template<typename Derived>
 class VisitorHelper {
 public:
+    VisitorHelper(GCData* gcData) : m_gcData(gcData) {}

[haraken, 2016/01/28 15:52:50]

Add explicit.

+
     // One-argument templated mark method. This uses the static type of
     // the argument to get the TraceTrait. By default, the mark method
     // of the TraceTrait just calls the virtual two-argument mark method on this
@@ -281,9 +284,13 @@ public:
         Derived::fromHelper(this)->registerWeakMembers(object, object, callback);
     }
 
+    inline GCData* gcData() const { return m_gcData; }
+
 private:
     template<typename T>
     static void handleWeakCell(Visitor* self, void* object);
+
+    GCData* m_gcData;
 };
 
 // Visitor is used to traverse the Blink object graph. Used for the
@@ -372,8 +379,9 @@ public:
     inline MarkingMode markingMode() const { return m_markingMode; }
 
 protected:
-    explicit Visitor(MarkingMode markingMode)
-        : m_markingMode(markingMode)
+    explicit Visitor(MarkingMode markingMode, GCData* gcData)
+        : VisitorHelper(gcData)
+        , m_markingMode(markingMode)
     { }
 
     virtual void registerWeakCellWithCallback(void**, WeakCallback) = 0;