[DevTools] New harness for inspector-protocol layout tests

third_party/WebKit/LayoutTests/inspector-protocol/console/console-dom-mutation-violations-expected.txt

+
 {
     method : Log.entryAdded
     params : {
         entry : {
             level : verbose
             lineNumber : 0
             source : violation
             stackTrace : {
                 callFrames : [
                     [0] : {
                         columnNumber : 14
                         functionName : 
                         lineNumber : 0
-                        scriptId : <string>
+                        scriptId : <scriptId>
                         url : 
                     }
                 ]
             }
             text : Added synchronous DOM mutation listener to a 'DOMSubtreeModified' event. Consider using MutationObserver to make the page more responsive.
-            timestamp : <number>
+            timestamp : <timestamp>
         }
     }
 }