[Sync] Support receiving early passphrase required information in Sync UI.

chrome/browser/ui/webui/options/sync_setup_handler.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/options/sync_setup_handler.h"
 
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/values.h"
 #include "chrome/browser/google/google_util.h"
@@ skipping 450 matching lines @@
 
   // If the wizard is already visible, focus it.
   if (service->get_wizard().IsVisible()) {
     web_ui_->CallJavascriptFunction("OptionsPage.closeOverlay");
     service->get_wizard().Focus();
     return;
   }
 
   // The user is trying to manually load a syncSetup URL.  We should bring up
   // either a login or a configure flow based on the state of sync.
-  if (service->HasSyncSetupCompleted())
-    service->get_wizard().Step(SyncSetupWizard::CONFIGURE);
-  else
+  if (service->HasSyncSetupCompleted()) {
+    if (service->IsPassphraseRequiredForDecryption()) {
+      service->get_wizard().Step(SyncSetupWizard::ENTER_PASSPHRASE);
+    } else {
+      service->get_wizard().Step(SyncSetupWizard::CONFIGURE);
+    }
+  } else {
     service->get_wizard().Step(SyncSetupWizard::GAIA_LOGIN);
+  }
 
   // Show the Sync Setup page.
   scoped_ptr<Value> page(Value::CreateStringValue("syncSetup"));
   web_ui_->CallJavascriptFunction("OptionsPage.navigateToPage", *page);
 }