Make Visitor use heap for the current thread

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 68a00f409ae26d4bb520ce76b69402bc325f29c0..5afb914ec1a467b14c4362cbe13baf0c4f34fa0a 100644
--- a/third_party/WebKit/Source/platform/heap/Visitor.h
+++ b/third_party/WebKit/Source/platform/heap/Visitor.h
@@ -119,6 +119,8 @@ public:
 template<typename Derived>
 class VisitorHelper {
 public:
+    VisitorHelper(ThreadState* state) : m_state(state) { }
+
     // 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
@@ -221,9 +223,14 @@ public:
         Derived::fromHelper(this)->registerWeakMembers(object, object, callback);
     }
 
+    inline ThreadState* state() const { return m_state; }
+    inline ThreadHeap& heap() const { return state()->heap(); }
+
 private:
     template<typename T>
     static void handleWeakCell(Visitor* self, void* object);
+
+    ThreadState* m_state;
 };
 
 // Visitor is used to traverse the Blink object graph. Used for the
@@ -313,8 +320,6 @@ public:
 
     inline MarkingMode getMarkingMode() const { return m_markingMode; }
 
-    inline ThreadHeap& heap() const { return m_state->heap(); }
-
 protected:
     Visitor(ThreadState*, MarkingMode);