[debugger] Basic scope functionality and exception events in wrapper

test/debugger/debug/regress/regress-crbug-609046.js

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug
 
 // Test that hidden scopes are correctly walked in the scope chain.
 
 var Debug = debug.Debug;
 var exception = null;
 var delegate = null;
 var done = false;
 
 function listener(event, exec_state, event_data, data) {
   if (event != Debug.DebugEvent.Break) return;
@@ skipping 11 matching lines @@
 Debug.setListener(listener);
 
 for(let a = 0; a < 3; a++) {
   debugger;
   eval();  // Force context-allocation of everything.
 }
 
 Debug.setListener(null);
 assertNull(exception);
 assertTrue(done);