Revert of [DevTools] Move 'this' evaluation from ExecutionContext to autocomplete.

third_party/WebKit/Source/devtools/front_end/sdk/RuntimeModel.js

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 526 matching lines @@
    */
   _evaluateGlobal(
       expression,
       objectGroup,
       includeCommandLineAPI,
       silent,
       returnByValue,
       generatePreview,
       userGesture,
       callback) {
+    if (!expression) {
+      // There is no expression, so the completion should happen against global properties.
+      expression = 'this';
+    }
+
     /**
      * @this {SDK.ExecutionContext}
      * @param {?Protocol.Error} error
      * @param {!Protocol.Runtime.RemoteObject} result
      * @param {!Protocol.Runtime.ExceptionDetails=} exceptionDetails
      */
     function evalCallback(error, result, exceptionDetails) {
       if (error) {
         console.error(error);
         callback(null);
@@ skipping 248 matching lines @@
         this._type === 'wheel';
   }
 };
 
 /** @enum {string} */
 SDK.EventListener.Origin = {
   Raw: 'Raw',
   Framework: 'Framework',
   FrameworkUser: 'FrameworkUser'
 };