Bug 1859445 - Do not include grandchilren into a job object. r=mhowell,win-reviewers,rkraesig,bobowen

Differential Revision: https://phabricator.services.mozilla.com/D191168

browser/app/winlauncher/LauncherProcessWin.cpp

@@ -93,12 +93,11 @@ static nsReturnRef<HANDLE> CreateJobAndAssignProcess(HANDLE aProcess) {
   nsAutoHandle empty;
   nsAutoHandle job(::CreateJobObjectW(nullptr, nullptr));
 
-  // Set JOB_OBJECT_LIMIT_BREAKAWAY_OK to allow the browser process
+  // Set JOB_OBJECT_LIMIT_SILENT_BREAKAWAY_OK to put only browser process
-  // to put child processes into a job on Win7, which does not support
+  // into a job without putting children of browser process into the job.
-  // nested jobs.  See CanUseJob() in sandboxBroker.cpp.
   JOBOBJECT_EXTENDED_LIMIT_INFORMATION jobInfo = {};
   jobInfo.BasicLimitInformation.LimitFlags =
-      JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE | JOB_OBJECT_LIMIT_BREAKAWAY_OK;
+      JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE | JOB_OBJECT_LIMIT_SILENT_BREAKAWAY_OK;
   if (!::SetInformationJobObject(job.get(), JobObjectExtendedLimitInformation,
                                  &jobInfo, sizeof(jobInfo))) {
     return empty.out();