DevTools: Split creating inspector stylesheet and adding a new rule into stylesheet in protocol.

LayoutTests/inspector/elements/styles/add-new-rule-inline-style-csp.html

Index: LayoutTests/inspector/elements/styles/add-new-rule-inline-style-csp.html
diff --git a/LayoutTests/inspector/elements/styles/add-new-rule-inline-style-csp.html b/LayoutTests/inspector/elements/styles/add-new-rule-inline-style-csp.html
index a18de1d125a903c4eaf17c3bd262319a20298154..2b539c7cd58c31ee4423ffde88b01158249aa61d 100644
--- a/LayoutTests/inspector/elements/styles/add-new-rule-inline-style-csp.html
+++ b/LayoutTests/inspector/elements/styles/add-new-rule-inline-style-csp.html
@@ -24,23 +24,17 @@ function test()
             function nodeCallback(node)
             {
                 nodeId = node.id;
-                WebInspector.cssModel.addRule(nodeId, "#inspected", successCallback, failureCallback);
+                InspectorTest.addNewRule("#inspected", successCallback);
             }
 
-            function successCallback(newRule, doesAffectSelectedNode)
+            function successCallback(styleRule)
             {
-                rule = newRule;
+                rule = styleRule.rule;
                 InspectorTest.addResult("=== Rule added ===");
                 InspectorTest.addResult(rule.selectorText + " {" + rule.style.cssText + "}");
                 InspectorTest.addResult("Selectors matching the (#inspected) node: " + InspectorTest.matchingSelectors(rule));
                 next();
             }
-
-            function failureCallback()
-            {
-                InspectorTest.addResult("[!] Failed to add rule.");
-                InspectorTest.completeTest();
-            }
         },
 
         function testAddProperty(next)