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

third_party/WebKit/Source/devtools/front_end/object_ui/JavaScriptAutocomplete.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 ObjectUI.JavaScriptAutocomplete = {};
 
 /** @typedef {{title:(string|undefined), items:Array<string>}} */
 ObjectUI.JavaScriptAutocomplete.CompletionGroup;
 
 /**
@@ skipping 52 matching lines @@
  */
 ObjectUI.JavaScriptAutocomplete._mapCompletions = function(text, query) {
   var mapMatch = text.match(/\.\s*(get|set|delete)\s*\(\s*$/);
   var executionContext = UI.context.flavor(SDK.ExecutionContext);
   if (!executionContext || !mapMatch)
     return Promise.resolve([]);
 
   var clippedExpression = ObjectUI.JavaScriptAutocomplete._clipExpression(text.substring(0, mapMatch.index));
   var fulfill;
   var promise = new Promise(x => fulfill = x);
-  executionContext.evaluate(clippedExpression, 'completion', true, true, false, false, false, evaluated);
+  executionContext.evaluate(clippedExpression || 'this', 'completion', true, true, false, false, false, evaluated);
   return promise;
 
   /**
    * @param {?SDK.RemoteObject} result
    * @param {!Protocol.Runtime.ExceptionDetails=} exceptionDetails
    */
   function evaluated(result, exceptionDetails) {
     if (!result || !!exceptionDetails || result.subtype !== 'map') {
       fulfill([]);
       return;
@@ skipping 99 matching lines @@
 
   if (!query && !expressionString && !force)
     return Promise.resolve([]);
 
   var fulfill;
   var promise = new Promise(x => fulfill = x);
   var selectedFrame = executionContext.debuggerModel.selectedCallFrame();
   if (!expressionString && selectedFrame)
     variableNamesInScopes(selectedFrame, receivedPropertyNames);
   else
-    executionContext.evaluate(expressionString, 'completion', true, true, false, false, false, evaluated);
+    executionContext.evaluate(expressionString || 'this', 'completion', true, true, false, false, false, evaluated);
 
   return promise;
   /**
    * @param {?SDK.RemoteObject} result
    * @param {!Protocol.Runtime.ExceptionDetails=} exceptionDetails
    */
   function evaluated(result, exceptionDetails) {
     if (!result || !!exceptionDetails) {
       fulfill([]);
       return;
@@ skipping 256 matching lines @@
   function itemComparator(naturalOrder, a, b) {
     var aStartsWithUnderscore = a.startsWith('_');
     var bStartsWithUnderscore = b.startsWith('_');
     if (aStartsWithUnderscore && !bStartsWithUnderscore)
       return 1;
     if (bStartsWithUnderscore && !aStartsWithUnderscore)
       return -1;
     return naturalOrder ? String.naturalOrderComparator(a, b) : a.localeCompare(b);
   }
 };