Override SigninManager::SignOut if force-signin is enabled.

chrome/browser/resources/settings/people_page/people_page.js

Index: chrome/browser/resources/settings/people_page/people_page.js
diff --git a/chrome/browser/resources/settings/people_page/people_page.js b/chrome/browser/resources/settings/people_page/people_page.js
index 5ec7f887782a64ae45aecfed3e901df791867242..34096fdfd88b628f1a8c7e4e9a2e50aba0401ddb 100644
--- a/chrome/browser/resources/settings/people_page/people_page.js
+++ b/chrome/browser/resources/settings/people_page/people_page.js
@@ -231,6 +231,7 @@ Polymer({
   onDisconnectClosed_: function() {
     if (settings.getCurrentRoute() == settings.Route.SIGN_OUT)
       settings.navigateToPreviousRoute();
+    window.dispatchEvent(new Event('signout-dialog-closed'));
   },
 
   /** @private */
@@ -247,9 +248,19 @@ Polymer({
   onDisconnectConfirm_: function() {
     var deleteProfile = !!this.syncStatus.domain ||
         (this.$.deleteProfile && this.$.deleteProfile.checked);
-    this.syncBrowserProxy_.signOut(deleteProfile);
-
+    // Close the dialog and navigate to previous route before signout so
+    // session restore does not restore to the signout dialog.
     this.$.disconnectDialog.close();
+    // If user visit the signout dialog by typing in the address bar, there
+    // will be no previous browsing history so signout right after the dialog
+    // being closed. Otherwise, signout after the route has been navigated to
+    // the privious one with a callback.
+    var signoutEvent = 'signout-dialog-closed';
+    if (settings.isPreviousRouteExistedInHistory())
+      signoutEvent = 'popstate';
+    listenOnce(window, signoutEvent, function callback() {
+      this.syncBrowserProxy_.signOut(deleteProfile);
+    }.bind(this));
   },
 
   /** @private */