Simplify isolates access during stack iteration (WAS: Move SafeStackFrameIterator::active_count_...)

src/v8threads.h

Index: src/v8threads.h
diff --git a/src/v8threads.h b/src/v8threads.h
index f1992ad765b1717416ee57211135a6f5da2ffa08..1266af7c698b2a999fd982cf905886800f0d77f6 100644
--- a/src/v8threads.h
+++ b/src/v8threads.h
@@ -78,7 +78,7 @@ class ThreadLocalTop;
 class ThreadVisitor {
  public:
   // ThreadLocalTop may be only available during this call.
-  virtual void VisitThread(ThreadLocalTop* top) = 0;
+  virtual void VisitThread(Isolate* isolate, ThreadLocalTop* top) = 0;
 
  protected:
   virtual ~ThreadVisitor() {}