function didReceiveTraceLog(traceLog)
        {
            if (!traceLog)
                return;
            this._alive = traceLog.alive;
            this._traceLogSize = traceLog.totalAvailableCalls;
            this._updateCapturingStatus();
        }
@param {?CanvasAgent.TraceLog} traceLog
@this {WebInspector.CanvasProfileHeader}