Devtools: [WIP] Implement enhanced devtools extension language APIs

Source/devtools/front_end/sources/WatchExpressionsSidebarPane.js

 /*
  * Copyright (C) IBM Corp. 2009  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 236 matching lines @@
      * @return {?string}
      */
     expression: function()
     {
         return this._expression;
     },
 
     update: function()
     {
         var currentExecutionContext = WebInspector.context.flavor(WebInspector.ExecutionContext);
-        if (currentExecutionContext && this._expression)
+        if (currentExecutionContext && this._expression) {
+            var location = currentExecutionContext.pauseLocation();
+            if (location) {
+                var activeMime = WebInspector.ResourceType.mimeFromUrl(location.source);
+                if (WebInspector.languageService.handles.transpile(activeMime)) {
+                    var expr = this._expression;
+                    var prom = this._pendingUpdate = WebInspector.languageService.transpile(activeMime, expr, location).then(result => {
+                        if (this._pendingUpdate !== prom) {
+                            //cancelled by another update
+                            return;
+                        }
+                        currentExecutionContext.evaluate(result, WebInspector.WatchExpression._watchObjectGroupId, false, true, false, false, this._createWatchExpression.bind(this));
+                    }).catch((e) => {
+                        currentExecutionContext.evaluate(expr, WebInspector.WatchExpression._watchObjectGroupId, false, true, false, false, this._createWatchExpression.bind(this));
+                    });
+                    return;
+                }
+            }
             currentExecutionContext.evaluate(this._expression, WebInspector.WatchExpression._watchObjectGroupId, false, true, false, false, this._createWatchExpression.bind(this));
+        }
     },
 
     startEditing: function()
     {
         this._editing = true;
         this._element.removeChild(this._objectPresentationElement);
         var newDiv = this._element.createChild("div");
         newDiv.textContent = this._nameElement.textContent;
         this._textPrompt = new WebInspector.ObjectPropertyPrompt();
         this._textPrompt.renderAsBlock();
@@ skipping 155 matching lines @@
             contextMenu.appendApplicableItems(this._result);
     },
 
     _copyValueButtonClicked: function()
     {
         InspectorFrontendHost.copyText(this._valueElement.textContent);
     },
 
     __proto__: WebInspector.Object.prototype
 }