Backend for css rule tracking

third_party/WebKit/Source/devtools/front_end/audits/AuditRules.js

Index: third_party/WebKit/Source/devtools/front_end/audits/AuditRules.js
diff --git a/third_party/WebKit/Source/devtools/front_end/audits/AuditRules.js b/third_party/WebKit/Source/devtools/front_end/audits/AuditRules.js
index 7731fac6ece3dbe29b5a60f872fbc2a67fdb342e..5fc71c15c286704792f2e7044c74f53644207276 100644
--- a/third_party/WebKit/Source/devtools/front_end/audits/AuditRules.js
+++ b/third_party/WebKit/Source/devtools/front_end/audits/AuditRules.js
@@ -373,6 +373,7 @@ WebInspector.AuditRules.UnusedCssRule.prototype = {
      */
     doRun: function(target, requests, result, callback, progress)
     {
+        WebInspector.CSSModel.fromTarget(target).startSelectorRecording(true);
         var domModel = WebInspector.DOMModel.fromTarget(target);
         var cssModel = WebInspector.CSSModel.fromTarget(target);
         if (!domModel || !cssModel) {
@@ -412,47 +413,69 @@ WebInspector.AuditRules.UnusedCssRule.prototype = {
                     return;
                 }
 
-                var inlineBlockOrdinal = 0;
-                var totalStylesheetSize = 0;
-                var totalUnusedStylesheetSize = 0;
-                var summary;
-
-                for (var i = 0; i < styleSheets.length; ++i) {
-                    var styleSheet = styleSheets[i];
-                    var unusedRules = [];
-                    for (var curRule = 0; curRule < styleSheet.rules.length; ++curRule) {
-                        var rule = styleSheet.rules[curRule];
-                        if (!testedSelectors[rule.selectorText] || foundSelectors[rule.selectorText])
-                            continue;
-                        unusedRules.push(rule.selectorText);
+                WebInspector.CSSModel.fromTarget(target).ruleListPromise().then(ruleListReceived);
+
+                function ruleListReceived(usedRulesList) {
+
+                    var inlineBlockOrdinal = 0;
+                    var totalStylesheetSize = 0;
+                    var totalUnusedStylesheetSize = 0;
+                    var summary;
+
+                    function getRange(range, URL) {
+                        return [range.startLine, range.startColumn, URL];
                     }
-                    totalStylesheetSize += styleSheet.rules.length;
-                    totalUnusedStylesheetSize += unusedRules.length;
 
-                    if (!unusedRules.length)
-                        continue;
+                    var cssModel = WebInspector.CSSModel.fromTarget(target);
 
-                    var resource = WebInspector.resourceForURL(styleSheet.sourceURL);
-                    var isInlineBlock = resource && resource.request && resource.request.resourceType() === WebInspector.resourceTypes.Document;
-                    var url = !isInlineBlock ? WebInspector.AuditRuleResult.linkifyDisplayName(styleSheet.sourceURL) : WebInspector.UIString("Inline block #%d", ++inlineBlockOrdinal);
-                    var pctUnused = Math.round(100 * unusedRules.length / styleSheet.rules.length);
-                    if (!summary)
-                        summary = result.addChild("", true);
-                    var entry = summary.addFormatted("%s: %d% is not used by the current page.", url, pctUnused);
+                    var testedRules = {};
+                    for (var i = 0; i < usedRulesList.length; ++i) {
+                        if (usedRulesList[i].wasUsed) {
+                            var styleSheetHeader = cssModel.styleSheetHeaderForId(usedRulesList[i].styleSheetId);
+                            testedRules[getRange(usedRulesList[i].range, styleSheetHeader.sourceURL)] = 1;
+                        }
+                    }
 
-                    for (var j = 0; j < unusedRules.length; ++j)
-                        entry.addSnippet(unusedRules[j]);
+                    for (var i = 0; i < styleSheets.length; ++i) {
+                        var styleSheet = styleSheets[i];
+                        var unusedRules = [];
 
-                    result.violationCount += unusedRules.length;
-                }
+                        for (var curRule = 0; curRule < styleSheet.rules.length; ++curRule) {
+                            var rule = styleSheet.rules[curRule];
 
-                if (!totalUnusedStylesheetSize)
-                    return callback(null);
+                            if (testedRules[getRange(rule.styleRange, styleSheet.sourceURL)])
+                                continue;
+                            unusedRules.push(rule);
+                        }
 
-                var totalUnusedPercent = Math.round(100 * totalUnusedStylesheetSize / totalStylesheetSize);
-                summary.value = WebInspector.UIString("%s rules (%d%) of CSS not used by the current page.", totalUnusedStylesheetSize, totalUnusedPercent);
+                        totalStylesheetSize += styleSheet.rules.length;
+                        totalUnusedStylesheetSize += unusedRules.length;
 
-                callback(result);
+                        if (!unusedRules.length)
+                            continue;
+
+                        var resource = WebInspector.resourceForURL(styleSheet.sourceURL);
+                        var isInlineBlock = resource && resource.request && resource.request.resourceType() === WebInspector.resourceTypes.Document;
+                        var url = !isInlineBlock ? WebInspector.AuditRuleResult.linkifyDisplayName(styleSheet.sourceURL) : WebInspector.UIString("Inline block #%d", ++inlineBlockOrdinal);
+                        var pctUnused = Math.round(100 * unusedRules.length / styleSheet.rules.length);
+                        if (!summary)
+                            summary = result.addChild("", true);
+                        var entry = summary.addFormatted("%s: %d% is not used by the current page.", url, pctUnused);
+
+                        for (var j = 0; j < unusedRules.length; ++j)
+                            entry.addSnippet(unusedRules[j].selectorText + "  Line: " + unusedRules[j].styleRange.startLine);
+
+                        result.violationCount += unusedRules.length;
+                    }
+
+                    if (!totalUnusedStylesheetSize)
+                        return callback(null);
+
+                    var totalUnusedPercent = Math.round(100 * totalUnusedStylesheetSize / totalStylesheetSize);
+                    summary.value = WebInspector.UIString("%s rules (%d%) of CSS not used by the current page.", totalUnusedStylesheetSize, totalUnusedPercent);
+
+                    callback(result);
+                }
             }
 
             /**