[Signin Error Dialog] (2/3) Added handlers and UI constructors

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

Index: chrome/browser/ui/webui/signin/get_desktop_browser.cc
diff --git a/chrome/browser/ui/webui/signin/get_desktop_browser.cc b/chrome/browser/ui/webui/signin/get_desktop_browser.cc
new file mode 100644
index 0000000000000000000000000000000000000000..32c216c21970090d0953378c513c7b97a278c7cc
--- /dev/null
+++ b/chrome/browser/ui/webui/signin/get_desktop_browser.cc
@@ -0,0 +1,19 @@
+// Copyright 2016 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/profiles/profile.h"
+#include "chrome/browser/ui/browser_finder.h"
+#include "content/public/browser/web_ui.h"
+
+namespace signin {
+
+Browser* GetDesktopBrowser(content::WebUI* web_ui) {
+  Browser* browser =
+      chrome::FindBrowserWithWebContents(web_ui->GetWebContents());
+  if (!browser)
+    browser = chrome::FindLastActiveWithProfile(Profile::FromWebUI(web_ui));
+  return browser;
+}
+
+}  // namespace signin