[debug] Add Eval scope type to inspector protocol

test/debugger/test-api.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.
 
 "use strict";
 
 // If true, prints all messages sent and received by inspector.
 const printProtocolMessages = false;
 
 // The active wrapper instance.
@@ skipping 372 matching lines @@
 
   execStateScopeType(type) {
     switch (type) {
       case "global": return this.ScopeType.Global;
       case "local": return this.ScopeType.Local;
       case "with": return this.ScopeType.With;
       case "closure": return this.ScopeType.Closure;
       case "catch": return this.ScopeType.Catch;
       case "block": return this.ScopeType.Block;
       case "script": return this.ScopeType.Script;
+      case "eval": return this.ScopeType.Eval;
       default: %AbortJS("Unexpected scope type");
     }
   }
 
   execStateScopeObjectProperty(serialized_scope, prop) {
     let found = null;
     for (let i = 0; i < serialized_scope.length; i++) {
       const elem = serialized_scope[i];
       if (elem.name == prop) {
         found = elem;
         break;
       }
     }
 
-    if (found == null) return { isUndefined : true }
+    if (found == null) return { isUndefined : () => true };
 
     const val = { value : () => found.value.value };
     return { value : () => val,
              isUndefined : () => found.value.type == "undefined"
            };
   }
 
   // Returns an array of property descriptors of the scope object.
   // This is in contrast to the original API, which simply passed object
   // mirrors.
@@ skipping 346 matching lines @@
     debug.instance = new DebugWrapper();
     debug.instance.enable();
   }
   return debug.instance;
 }});
 
 Object.defineProperty(debug, 'ScopeType', { get: function() {
   const instance = debug.Debug;
   return instance.ScopeType;
 }});