[DevTools] Show blocked requests in network log.

Source/devtools/protocol.json

 {
     "version": { "major": "1", "minor": "1" },
     "domains": [{
         "domain": "Inspector",
         "hidden": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications.",
@@ skipping 1529 matching lines @@
                 ]
             },
             {
                 "name": "loadingFailed",
                 "description": "Fired when HTTP request has failed to load.",
                 "parameters": [
                     { "name": "requestId", "$ref": "RequestId", "description": "Request identifier." },
                     { "name": "timestamp", "$ref": "Timestamp", "description": "Timestamp." },
                     { "name": "type", "$ref": "Page.ResourceType", "description": "Resource type." },
                     { "name": "errorText", "type": "string", "description": "User friendly error message." },
-                    { "name": "canceled", "type": "boolean", "optional": true, "description": "True if loading was canceled." }
+                    { "name": "canceled", "type": "boolean", "optional": true, "description": "True if loading was canceled." },
+                    { "name": "blocked", "type": "boolean", "optional": true, "description": "True if loading was blocked by inspector." }
                 ]
             },
             {
                 "name": "webSocketWillSendHandshakeRequest",
                 "description": "Fired when WebSocket is about to initiate handshake.",
                 "parameters": [
                     { "name": "requestId", "$ref": "RequestId", "description": "Request identifier." },
                     { "name": "timestamp", "$ref": "Timestamp", "description": "Timestamp." },
                     { "name": "wallTime", "$ref": "Timestamp", "hidden": true, "description": "UTC Timestamp." },
                     { "name": "request", "$ref": "WebSocketRequest", "description": "WebSocket request data." }
@@ skipping 3610 matching lines @@
                 ],
                 "returns": [
                     { "name": "accessibilityNode", "$ref": "AXNode", "description": "The <code>Accessibility.AXNode</code> for this DOM node, if it exists.", "optional": true }
                 ],
                 "description": "Fetches the accessibility node for this DOM node, if it exists.",
                 "hidden": true
             }
         ]
     }]
 }