[XSS] Skip naps when InjectionChecker runs in its own worker.

src/lib/Timing.js

@@ -31,7 +31,7 @@ class Timing {
         throw new TimingException(`Timing: exceeded ${this.longTime}ms timeout`);
       }
       this.calls = 0;
-      await Timing.sleep(this.pauseTime);
+      if (this.pauseTime > 0) await Timing.sleep(this.pauseTime);
       this.lastPause = Date.now();
       return true;
     }

src/xss/InjectionCheckWorker.js

@@ -36,7 +36,7 @@ include("InjectionChecker.js");
 
       let {timing} = ic;
       timingsMap.set(request.requestId, timing);
-      timing.fatalTimeout = true;
+      timing.pauseTime = 0; // skip the default 20ms nap
 
       let postInjection = xssReq.isPost &&
           request.requestBody && request.requestBody.formData &&