DevTools: add test to verify matched styles for :host selector

LayoutTests/inspector-protocol/css/css-protocol-test.js

 function initialize_cssTest()
 {
 
 InspectorTest.dumpStyleSheetText = function(styleSheetId, callback)
 {
     InspectorTest.sendCommandOrDie("CSS.getStyleSheetText", { styleSheetId: styleSheetId }, onStyleSheetText);
     function onStyleSheetText(result)
     {
         InspectorTest.log("==== Style sheet text ====");
         InspectorTest.log(result.text);
@@ skipping 102 matching lines @@
         log(4, propertyLine);
     }
     log(0, "}");
 };
 
 InspectorTest.displayName = function(url)
 {
     return url.substr(url.lastIndexOf("/") + 1);
 };
 
-InspectorTest.loadAndDumpMatchingRules = function(nodeId, callback)
+InspectorTest.loadAndDumpMatchingRulesForNode = function(nodeId, callback)
 {
-    InspectorTest.requestNodeId(nodeId, nodeIdLoaded);
-
-    function nodeIdLoaded(nodeId)
-    {
-        InspectorTest.sendCommandOrDie("CSS.getMatchedStylesForNode", { "nodeId": nodeId }, matchingRulesLoaded);
-    }
+    InspectorTest.sendCommandOrDie("CSS.getMatchedStylesForNode", { "nodeId": nodeId }, matchingRulesLoaded);
 
     function matchingRulesLoaded(result)
     {
         InspectorTest.log("Dumping matched rules: ");
         var ruleMatches = result.matchedCSSRules;
         for (var i = 0; i < ruleMatches.length; ++i) {
             var ruleMatch = ruleMatches[i];
             var origin = ruleMatch.rule.origin;
             if (origin !== "inspector" && origin !== "regular")
                 continue;
             InspectorTest.dumpRuleMatch(ruleMatch);
         }
         callback();
     }
 }
 
+InspectorTest.loadAndDumpMatchingRules = function(selector, callback)
+{
+    InspectorTest.requestNodeId(selector, nodeIdLoaded);
+
+    function nodeIdLoaded(nodeId)
+    {
+        InspectorTest.loadAndDumpMatchingRulesForNode(nodeId, callback);
+    }
+}
+
 }