Make the new Gaia password separated signin flow modal.

chrome/browser/ui/webui/signin/inline_login_handler_impl.cc

Index: chrome/browser/ui/webui/signin/inline_login_handler_impl.cc
diff --git a/chrome/browser/ui/webui/signin/inline_login_handler_impl.cc b/chrome/browser/ui/webui/signin/inline_login_handler_impl.cc
index ab0352404cb8797d98b1503de77a37b5008c8aa6..9ec70e8788a55d4d0fa92ae77d77b1f4149332b3 100644
--- a/chrome/browser/ui/webui/signin/inline_login_handler_impl.cc
+++ b/chrome/browser/ui/webui/signin/inline_login_handler_impl.cc
@@ -713,6 +713,12 @@ void InlineLoginHandlerImpl::FinishCompleteLogin(
     const FinishCompleteLoginParams& params,
     Profile* profile,
     Profile::CreateStatus status) {
+  if (params.handler && switches::UsePasswordSeparatedSigninFlow()) {
+    Browser* browser = params.handler->GetDesktopBrowser();
+    if (browser)
+      browser->window()->CloseModalSigninWindow();
+  }
+
   // When doing a SAML sign in, this email check may result in a false
   // positive.  This happens when the user types one email address in the
   // gaia sign in page, but signs in to a different account in the SAML sign in