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

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

Index: LayoutTests/inspector-protocol/css/css-protocol-test.js
diff --git a/LayoutTests/inspector-protocol/css/css-protocol-test.js b/LayoutTests/inspector-protocol/css/css-protocol-test.js
index 4f159df4ff26ba1ac9594f5e46fb1f3c445dec20..07730e1d18aa70d23478e561b7280d8529620239 100644
--- a/LayoutTests/inspector-protocol/css/css-protocol-test.js
+++ b/LayoutTests/inspector-protocol/css/css-protocol-test.js
@@ -120,14 +120,9 @@ 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)
     {
@@ -144,4 +139,14 @@ InspectorTest.loadAndDumpMatchingRules = function(nodeId, callback)
     }
 }
 
+InspectorTest.loadAndDumpMatchingRules = function(selector, callback)
+{
+    InspectorTest.requestNodeId(selector, nodeIdLoaded);
+
+    function nodeIdLoaded(nodeId)
+    {
+        InspectorTest.loadAndDumpMatchingRulesForNode(nodeId, callback);
+    }
+}
+
 }