DevTools: introduce API for the Common.FormatterWorkerPool.

third_party/WebKit/Source/devtools/front_end/sass/SASSSupport.js

 // Copyright 2015 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.
 Sass.SASSSupport = {};
 
 /**
  * @param {string} url
  * @param {string} content
  * @return {!Promise<!Sass.SASSSupport.AST>}
  */
 Sass.SASSSupport.parseSCSS = function(url, content) {
   var text = new Common.Text(content);
   var document = new Sass.SASSSupport.ASTDocument(url, text);
 
-  return Common.formatterWorkerPool.runTask('parseSCSS', {content: content}).then(onParsed);
+  return Common.formatterWorkerPool.parseSCSS(content).then(onParsed);
 
   /**
-   * @param {?MessageEvent} event
+   * @param {!Array<!Common.FormatterWorkerPool.SCSSRule>} rulePayloads
    * @return {!Sass.SASSSupport.AST}
    */
-  function onParsed(event) {
-    if (!event)
-      return new Sass.SASSSupport.AST(document, []);
-    var data = /** @type {!Array<!Object>} */ (event.data);
+  function onParsed(rulePayloads) {
     var rules = [];
-    for (var i = 0; i < data.length; ++i) {
-      var rulePayload = data[i];
+    for (var i = 0; i < rulePayloads.length; ++i) {
+      var rulePayload = rulePayloads[i];
       var selectors = rulePayload.selectors.map(createTextNode);
       var properties = rulePayload.properties.map(createProperty);
       var range = Common.TextRange.fromObject(rulePayload.styleRange);
       var rule = new Sass.SASSSupport.Rule(document, selectors, range, properties);
       rules.push(rule);
     }
     return new Sass.SASSSupport.AST(document, rules);
   }
 
   /**
@@ skipping 620 matching lines @@
     mapping.set(oldProperty.name, newProperty.name);
     mapping.set(oldProperty.value, newProperty.value);
     if (oldProperty.name.text.trim() !== newProperty.name.text.trim())
       addChange(T.NameChanged, oldRule, newRule, oldPropertyIndex, newPropertyIndex);
     if (oldProperty.value.text.trim() !== newProperty.value.text.trim())
       addChange(T.ValueChanged, oldRule, newRule, oldPropertyIndex, newPropertyIndex);
     if (oldProperty.disabled !== newProperty.disabled)
       addChange(T.PropertyToggled, oldRule, newRule, oldPropertyIndex, newPropertyIndex);
   }
 };