DevTools: Send async stack trace with Network.Initiator.

Source/devtools/protocol.json

 {
     "version": { "major": "1", "minor": "1" },
     "domains": [{
         "domain": "Inspector",
         "hidden": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications."
@@ skipping 1120 matching lines @@
                 ]
             },
             {
                 "id": "Initiator",
                 "type": "object",
                 "description": "Information about the request initiator.",
                 "properties": [
                     { "name": "type", "type": "string", "enum": ["parser", "script", "other"], "description": "Type of this initiator." },
                     { "name": "stackTrace", "$ref": "Console.StackTrace", "optional": true, "description": "Initiator JavaScript stack trace, set for Script only." },
                     { "name": "url", "type": "string", "optional": true, "description": "Initiator URL, set for Parser type only." },
-                    { "name": "lineNumber", "type": "number", "optional": true, "description": "Initiator line number, set for Parser type only." }
+                    { "name": "lineNumber", "type": "number", "optional": true, "description": "Initiator line number, set for Parser type only." },
+                    { "name": "asyncStackTrace", "$ref": "Console.AsyncStackTrace", "optional": true, "description": "Initiator asynchronous JavaScript stack trace, if available.", "hidden": true }
                 ]
             }
         ],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables network tracking, network events will now be delivered to the client."
             },
             {
                 "name": "disable",
@@ skipping 3120 matching lines @@
             {
                 "name": "dataAvailable",
                 "parameters": [
                     {"name": "value", "type": "array", "items": { "$ref": "PowerEvent" }, "description": "List of power events." }
                 ],
                 "handlers": ["browser", "frontend"]
             }
         ]
     }]
 }