DevTools: Get rid of synchronous XHRs in the frontend code

Source/devtools/front_end/sdk/CSSParser.js

 /**
  * Copyright 2014 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.
  */
 
 /**
  * @constructor
  * @extends {WebInspector.Object}
  */
 WebInspector.CSSParser = function()
 {
-    this._worker = Runtime.startWorker("script_formatter_worker");
-    this._worker.onmessage = this._onRuleChunk.bind(this);
     this._rules = [];
+    Runtime.startWorker("script_formatter_worker").then(this._init.bind(this));
 }
 
 WebInspector.CSSParser.Events = {
     RulesParsed: "RulesParsed"
 }
 
 WebInspector.CSSParser.prototype = {
+    _init: function(worker)

[pfeldman, 2014/11/07 14:51:17]

Here and in other _inits, please annotate worker.

[apavlov, 2014/11/10 07:44:11]

Done.

+    {
+        this._worker = worker;
+        if (this._disposed) {
+            this.dispose();
+            return;
+        }
+        this._worker.onmessage = this._onRuleChunk.bind(this);
+        this._parseStoredText();
+    },
+
     /**
      * @param {!WebInspector.CSSStyleSheetHeader} styleSheetHeader
      * @param {function(!Array.<!WebInspector.CSSParser.Rule>)=} callback
      */
     fetchAndParse: function(styleSheetHeader, callback)
     {
         this._lock();
         this._finishedCallback = callback;
         styleSheetHeader.requestContent(this._innerParse.bind(this));
     },
 
     /**
      * @param {string} text
      * @param {function(!Array.<!WebInspector.CSSParser.Rule>)=} callback
      */
     parse: function(text, callback)

[pfeldman, 2014/11/07 14:51:17]

Since this is async, you should promisify it as well and get rid of this._text

[apavlov, 2014/11/10 07:44:11]

Done.

     {
         this._lock();
         this._finishedCallback = callback;
         this._innerParse(text);
     },
 
     dispose: function()
     {
         if (this._worker) {
             this._worker.terminate();
             delete this._worker;
+        } else {
+            this._disposed = true;
         }
     },
 
     /**
      * @return {!Array.<!WebInspector.CSSParser.Rule>}
      */
     rules: function()
     {
         return this._rules;
     },
 
     _lock: function()
     {
         console.assert(!this._parsingStyleSheet, "Received request to parse stylesheet before previous was completed.");
         this._parsingStyleSheet = true;
     },
 
     _unlock: function()
     {
         delete this._parsingStyleSheet;
     },
 
     /**
      * @param {?string} text
      */
     _innerParse: function(text)
     {
+        this._text = text;
+        if (this._worker)
+            this._parseStoredText();
+    },
+
+    _parseStoredText: function()
+    {
+        if (this._text === undefined)
+            return;
         this._rules = [];
-        this._worker.postMessage({ method: "parseCSS", params: { content: text } });
+        this._worker.postMessage({ method: "parseCSS", params: { content: this._text } });
+        delete this._text;
     },
 
     /**
      * @param {!MessageEvent} event
      */
     _onRuleChunk: function(event)
     {
         var data = /** @type {!WebInspector.CSSParser.DataChunk} */ (event.data);
         var chunk = data.chunk;
         for (var i = 0; i < chunk.length; ++i)
@@ skipping 31 matching lines @@
 
 /**
  * @typedef {(WebInspector.CSSParser.StyleRule|WebInspector.CSSParser.AtRule)}
  */
 WebInspector.CSSParser.Rule;
 
 /**
  * @typedef {{name: string, value: string}}
  */
 WebInspector.CSSParser.Property;