Remove static CallCompletedCallback handlers

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 418c22fa523b99862eff8720458ef557186673d3..48ea31f3d92f14b797f221870b7007bacf6182ab 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -1111,6 +1111,10 @@ class Isolate {
   // Get (and lazily initialize) the registry for per-isolate symbols.
   Handle<JSObject> GetSymbolRegistry();
 
+  void AddCallCompletedCallback(CallCompletedCallback callback);
+  void RemoveCallCompletedCallback(CallCompletedCallback callback);
+  void FireCallCompletedCallback();
+
  private:
   Isolate();
 
@@ -1331,6 +1335,9 @@ class Isolate {
 
   int next_optimization_id_;
 
+  // List of callbacks when a Call completes.
+  List<CallCompletedCallback> call_completed_callbacks_;
+
   friend class ExecutionAccess;
   friend class HandleScopeImplementer;
   friend class IsolateInitializer;