[DevTools] Make inspector-protocol tests work with messages passed as objects.

LayoutTests/http/tests/inspector-protocol/resources/protocol-test.html

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 Copyright (C) 2012 Samsung Electronics. All rights reserved.
 
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@@ skipping 118 matching lines @@
  * @param {function({object} messageObject)=} handler
  */
 InspectorTest.sendRawCommand = function(command, handler)
 {
     this._dispatchTable[++this._requestId] = handler;
     InspectorFrontendHost.sendMessageToBackend(command);
     return this._requestId;
 }
 
 /**
- * @param {string} message
+ * @param {string|!Object} messageOrObject
  */
-InspectorFrontendAPI.dispatchMessage = function(message)
+InspectorFrontendAPI.dispatchMessage = function(messageOrObject)
 {
     if (InspectorTest._dumpInspectorProtocolMessages)
-        testRunner.logToStderr("backend: " + message);
-    var messageObject = JSON.parse(message);
+        testRunner.logToStderr("backend: " + (typeof messageOrObject === "string" ? messageOrObject : JSON.stringify(messageOrObject)));
+    var messageObject = (typeof messageOrObject === "string" ? JSON.parse(messageOrObject) : messageOrObject);
     var messageId = messageObject["id"];
     try {
         if (typeof messageId === "number") {
             var handler = InspectorTest._dispatchTable[messageId];
             if (handler && typeof handler === "function")
                 handler(messageObject);
         } else {
             var eventName = messageObject["method"];
             var eventHandler = InspectorTest.eventHandler[eventName];
             if (eventHandler)
@@ skipping 161 matching lines @@
 function enableInspectorAgent()
 {
     InspectorTest.sendCommand("Inspector.enable", { });
 }
 
 window.addEventListener("load", enableInspectorAgent, false);
 
 </script>
 </head>
 </html>