Use STARTF_FORCEOFFFEEDBACK flag when starting Windows child processes to...

Use STARTF_FORCEOFFFEEDBACK flag when starting Windows child processes to prevent app starting cursor.

R=forshaw@chromium.org

Bug: 650931
Change-Id: I9894f929ec2f662cdd10046789f854242c95021a
Reviewed-on: https://chromium-review.googlesource.com/899367
Commit-Queue: James Forshaw <forshaw@chromium.org>
Reviewed-by: James Forshaw <forshaw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#547696}

AUTHORS

@@ -112,6 +112,7 @@ Bernhard M. Wiedemann <bwiedemann@suse.de>
 Bhagirathi Satpathy <bhagirathi.s@samsung.com>
 Bhanukrushana Rout <b.rout@samsung.com>
 Biljith Jayan <billy.jayan@samsung.com>
+Bob Owen <bowen@mozilla.com>
 Bobby Powers <bobbypowers@gmail.com>
 Branden Archer <bma4@zips.uakron.edu>
 Brendan Kirby <brendan.kirby@imgtec.com>

sandbox/win/src/broker_services.cc

@@ -318,6 +318,10 @@ ResultCode BrokerServicesBase::SpawnTarget(const wchar_t* exe_path,
 
   // Initialize the startup information from the policy.
   base::win::StartupInformation startup_info;
+
+  // We don't want any child processes causing the IDC_APPSTARTING cursor.
+  startup_info.startup_info()->dwFlags |= STARTF_FORCEOFFFEEDBACK;
+
   // The liftime of |mitigations|, |inherit_handle_list| and
   // |child_process_creation| have to be at least as long as
   // |startup_info| because |UpdateProcThreadAttribute| requires that