Start moving signin code out of browser/sync.

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

Index: chrome/browser/ui/webui/signin/login_ui_service.cc
diff --git a/chrome/browser/ui/webui/signin/login_ui_service.cc b/chrome/browser/ui/webui/signin/login_ui_service.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d954277b96362dc0dc1dfc597c773e443e7402d1
--- /dev/null
+++ b/chrome/browser/ui/webui/signin/login_ui_service.cc
@@ -0,0 +1,60 @@
+// Copyright (c) 2012 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/signin/login_ui_service.h"
+
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/browser_window.h"
+#include "chrome/common/url_constants.h"
+#include "content/browser/renderer_host/render_view_host.h"
+#include "content/public/browser/render_view_host_delegate.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_ui.h"
+
+LoginUIService::LoginUIService(Profile* profile)
+    : ui_(NULL),
+      profile_(profile) {
+}
+
+LoginUIService::~LoginUIService() {}
+
+void LoginUIService::SetLoginUI(content::WebUI* ui) {
+  DCHECK(!current_login_ui() || current_login_ui() == ui);
+  ui_ = ui;
+}
+
+void LoginUIService::ResetLoginUI(content::WebUI* ui) {
+  if (current_login_ui() == ui)
+    ui_ = NULL;

[tim (not reviewing), 2012/02/14 17:22:29]

Oh, I see.  Wait, when is this called?

Could we instead name this function OnWebUIGoingAway or something to that effect
(BeingClosed, etc)... that makes it more clear that we're just telling |this|
about some event that it may want to take action on, based on the parameter.

[Andrew T Wilson (Slow), 2012/02/14 20:52:36]

I think the renaming addressed this. Let me know if you want further renaming.

+}
+
+void LoginUIService::FocusLoginUI() {
+  if (!ui_) {
+    NOTREACHED() << "FocusLoginUI() called with no active login UI";
+    return;
+  }
+  ui_->GetWebContents()->GetRenderViewHost()->delegate()->Activate();
+}
+
+void LoginUIService::ShowLoginUI() {
+  if (ui_) {
+    // We already have active login UI - make it visible.
+    FocusLoginUI();
+    return;
+  }
+
+  // Need to navigate to the settings page and display the UI.
+  if (profile_) {
+    Browser* browser = BrowserList::GetLastActiveWithProfile(profile_);
+    if (!browser) {
+      browser = Browser::Create(profile_);
+      browser->ShowOptionsTab(chrome::kSyncSetupSubPage);
+      browser->window()->Show();
+    } else {
+      browser->ShowOptionsTab(chrome::kSyncSetupSubPage);
+    }
+  }
+}