DevTools: represent ComputedStyle with simple Map

Source/devtools/front_end/audits/AuditRules.js

 /*
  * Copyright (C) 2010 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 879 matching lines @@
                 for (var frameOwnerCandidate = node; frameOwnerCandidate; frameOwnerCandidate = frameOwnerCandidate.parentNode) {
                     if (frameOwnerCandidate.baseURL) {
                         var completeSrc = WebInspector.ParsedURL.completeURL(frameOwnerCandidate.baseURL, src);
                         break;
                     }
                 }
             }
             if (completeSrc)
                 src = completeSrc;
 
-            if (styles.computedStyle.getPropertyValue("position") === "absolute")
+            if (styles.computedStyle.get("position") === "absolute")
                 return;
 
             if (styles.attributesStyle) {
                 var widthFound = !!styles.attributesStyle.getLiveProperty("width");
                 var heightFound = !!styles.attributesStyle.getLiveProperty("height");
             }
 
             var inlineStyle = styles.inlineStyle;
             if (inlineStyle) {
                 if (inlineStyle.getPropertyValue("width") !== "")
@@ skipping 43 matching lines @@
             /**
              * @param {?WebInspector.CSSStyleModel.MatchedStyleResult} matchedStyleResult
              */
             function matchedCallback(matchedStyleResult)
             {
                 if (matchedStyleResult)
                     targetResult.matchedCSSRules = matchedStyleResult.matchedCSSRules;
             }
 
             /**
-             * @param {?WebInspector.CSSStyleDeclaration} computedStyle
+             * @param {?Map.<string, string>} computedStyle
              */
             function computedCallback(computedStyle)
             {
                 targetResult.computedStyle = computedStyle;
             }
 
             if (!nodeIds || !nodeIds.length)
                 doneCallback();
 
             var nodePromises = [];
@@ skipping 672 matching lines @@
         result.violationCount = badUrls.length;
     },
 
     _collectorCallback: function(matchingResourceData, request, cookie)
     {
         matchingResourceData[request.url] = (matchingResourceData[request.url] || 0) + cookie.size();
     },
 
     __proto__: WebInspector.AuditRules.CookieRuleBase.prototype
 }