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..58cdd0c02349b94502e44e20c310ae7825eaaac6 100644
--- a/chrome/browser/resources/settings/people_page/people_page.js
+++ b/chrome/browser/resources/settings/people_page/people_page.js
@@ -247,9 +247,13 @@ Polymer({
   onDisconnectConfirm_: function() {
     var deleteProfile = !!this.syncStatus.domain ||
         (this.$.deleteProfile && this.$.deleteProfile.checked);
-    this.syncBrowserProxy_.signOut(deleteProfile);
-
-    this.$.disconnectDialog.close();
+    // Navigate to previous route before signout so session restore does
+    // not restore to the signout dialog. Dialog will be automatically
+    // closed by the route change.
+    settings.navigateToPreviousRoute();
+    setTimeout(function() {

[tommycli, 2016/11/01 17:28:54]

Thinking further on this: I think using setTimeout here is wrong. We have to
wait until the browse has finished its Back navigation.

So the right thing to do would be:

window.addEventListener('popstate', function callback() {
  window.removeEventListener('popstate', callback);
  this.syncBrowserProxy_.signOut(deleteProfile);
}.bind(this));

See if that fixes your tests too.

[Dan Beam, 2016/11/01 18:51:38]

see also: listenOnce()

+       this.syncBrowserProxy_.signOut(deleteProfile);
+    }.bind(this));
   },
 
   /** @private */