Debug.msTraceAsyncCallbackStarting - Archive of obsolete content
remarks call this function in the callback function for the asynchronous operation after the call to debug.mstraceasyncoperationcompleted.
... function asyncwrapperfunction() { var opid = debug.mstraceasyncoperationstarting('async trace'); dosomethingasync().then(function (result) { debug.mstraceasyncoperationcompleted(opid, debug.ms_async_op_status_success); debug.mstraceasynccallbackstarting(opid); // process result of async operation.
... }, function (error) { debug.mstraceasyncoperationcompleted(opid, debug.ms_async_op_status_error); debug.mstraceasynccallbackstarting(opid); }); debug.mstraceasynccallbackcompleted(); } function dosomethingasync() { return winjs.promise.as(true); } asyncwrapperfunction(); requirements supported in the internet explorer 11 standards document mode.

Debug.msTraceAsyncCallbackCompleted - Archive of obsolete content
function asyncwrapperfunction() { var opid = debug.mstraceasyncoperationstarting('async trace'); dosomethingasync().then(function (result) { debug.mstraceasyncoperationcompleted(opid, debug.ms_async_op_status_success); debug.mstraceasynccallbackstarting(opid); // process result of async operation.
... }, function (error) { debug.mstraceasyncoperationcompleted(opid, debug.ms_async_op_status_error); debug.mstraceasynccallbackstarting(opid); }); debug.mstraceasynccallbackcompleted(); } function dosomethingasync() { return winjs.promise.as(true); } asyncwrapperfunction(); requirements supported in the internet explorer 11 standards document mode.

WebRequest.jsm
usage to import webrequest, use code like: let {webrequest} = cu.import("resource://gre/modules/webrequest.jsm", {}); the webrequest object has the following properties, each of which corresponds to a specific stage in executing a web request: onbeforerequest onbeforesendheaders onsendheaders onheadersreceived onresponsestarted oncompleted each of these objects defines two functions: addlistener(callback, filter, opt_extrainfospec) removelistener(callback) adding listeners use addlistener to add a listener to a particular event.
... oncompleted triggered when the response has been received.

Debug - Archive of obsolete content
debug.mstraceasyncoperationcompleted indicates that an asynchronous operation has completed.