Make sure incognito mode is enabled for GCPW sign-in

Bug: 1124834
Change-Id: I659d866ed4e697bc189edd35789b2179c6d913ea
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2392774Reviewed-by: Drew Wilson <atwilson@chromium.org>
Reviewed-by: Owen Min <zmin@chromium.org>
Reviewed-by: Rakesh Soma <rakeshsoma@google.com>
Commit-Queue: Yusuf Sengul <yusufsn@google.com>
Cr-Commit-Position: refs/heads/master@{#804998}

chrome/browser/profiles/incognito_mode_policy_handler.cc

@@ -4,11 +4,14 @@
 
 #include "chrome/browser/profiles/incognito_mode_policy_handler.h"
 
+#include "base/command_line.h"
 #include "base/notreached.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/values.h"
+#include "build/build_config.h"
 #include "chrome/browser/prefs/incognito_mode_prefs.h"
 #include "chrome/common/pref_names.h"
+#include "chrome/credential_provider/common/gcp_strings.h"
 #include "components/policy/core/browser/policy_error_map.h"
 #include "components/policy/core/common/policy_map.h"
 #include "components/policy/policy_constants.h"
@@ -55,6 +58,17 @@ bool IncognitoModePolicyHandler::CheckPolicySettings(const PolicyMap& policies,
 
 void IncognitoModePolicyHandler::ApplyPolicySettings(const PolicyMap& policies,
                                                      PrefValueMap* prefs) {
+#if defined(OS_WIN)
+  // When browser starts with GCPW sign-in flag, it runs in incognito mode and
+  // gaia login page is loaded. With this flag, user can't use Chrome normally.
+  // However GCPW can't work in non-incognito mode and policy setting prevents
+  // Chrome from launching in incognito mode.To make this work, we should ignore
+  // setting inconito mode policy if GCPW sign-in flag is present.
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          ::credential_provider::kGcpwSigninSwitch))
+    return;
+#endif
+
   const base::Value* availability =
       policies.GetValue(key::kIncognitoModeAvailability);
   const base::Value* deprecated_enabled =