Make headless_shell target compile for Windows

headless/public/util/deterministic_dispatcher.cc

Index: headless/public/util/deterministic_dispatcher.cc
diff --git a/headless/public/util/deterministic_dispatcher.cc b/headless/public/util/deterministic_dispatcher.cc
index d6314469b944880b725b2f6aa8107a08b6ea4b7f..626279dd8b335ca2e9cbfb838884a107b9a6ced3 100644
--- a/headless/public/util/deterministic_dispatcher.cc
+++ b/headless/public/util/deterministic_dispatcher.cc
@@ -89,7 +89,7 @@ void DeterministicDispatcher::MaybeDispatchJobLocked() {
 
 void DeterministicDispatcher::MaybeDispatchJobOnIOThreadTask() {
   Request request;
-  net::Error job_status;
+  net::Error job_status = net::ERR_FAILED;
 
   {
     base::AutoLock lock(lock_);