[DevTools] Show blocked requests in Network panel.

Source/devtools/front_end/sdk/NetworkRequest.js

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 36 matching lines @@
     this._requestId = requestId;
     this.url = url;
     this._documentURL = documentURL;
     this._frameId = frameId;
     this._loaderId = loaderId;
     /** @type {?NetworkAgent.Initiator} */
     this._initiator = initiator;
     this._issueTime = -1;
     this._startTime = -1;
     this._endTime = -1;
+    /** @type {!NetworkAgent.BlockedReason|undefined} */
+    this._blockedReason = undefined;
 
     this.statusCode = 0;
     this.statusText = "";
     this.requestMethod = "";
     this.requestTime = 0;
     this.protocol = "";
     this.mixedContentType = "";
 
     /** @type {?NetworkAgent.ResourcePriority} */
     this._initialPriority = null;
@@ skipping 316 matching lines @@
     {
         return this._canceled;
     },
 
     set canceled(x)
     {
         this._canceled = x;
     },
 
     /**
+     * @return {!NetworkAgent.BlockedReason|undefined}
+     */
+    blockedReason: function()
+    {
+        return this._blockedReason;
+    },
+
+    /**
+     * @param {!NetworkAgent.BlockedReason} reason
+     */
+    setBlockedReason: function(reason)
+    {
+        this._blockedReason = reason;
+    },
+
+    /**
      * @return {boolean}
      */
-    get blocked()
+    wasBlocked: function()
     {
-        return this._blocked;
-    },
-
-    set blocked(x)
-    {
-        this._blocked = x;
+        return !!this._blockedReason;
     },
 
     /**
      * @return {boolean}
      */
     cached: function()
     {
         return (!!this._fromMemoryCache || !!this._fromDiskCache) && !this._transferSize;
     },
 
@@ skipping 718 matching lines @@
         this.dispatchEventToListeners(WebInspector.NetworkRequest.Events.EventSourceMessageAdded, message);
     },
 
     replayXHR: function()
     {
         this.target().networkAgent().replayXHR(this.requestId);
     },
 
     __proto__: WebInspector.SDKObject.prototype
 }