Implement new password separated sign in flow for chrome desktop.

components/signin/core/common/profile_management_switches.cc

Index: components/signin/core/common/profile_management_switches.cc
diff --git a/components/signin/core/common/profile_management_switches.cc b/components/signin/core/common/profile_management_switches.cc
index 6d58837d6524fffdfd513194ed88e1a5fb44aeb4..692f20cf3a8ad4a6680f58eaa9870d4d960876fe 100644
--- a/components/signin/core/common/profile_management_switches.cc
+++ b/components/signin/core/common/profile_management_switches.cc
@@ -159,6 +159,11 @@ bool IsNewProfileManagementPreviewEnabled() {
   return false;
 }
 
+bool UseNewGaiaFlow() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableNewGaiaSigninFlow);
+}
+
 void EnableNewAvatarMenuForTesting(base::CommandLine* command_line) {
   command_line->AppendSwitch(switches::kEnableNewAvatarMenu);
   DCHECK(!command_line->HasSwitch(switches::kDisableNewAvatarMenu));