Add a function to send scripts from a browsertest to an extension's background page.

chrome/browser/extensions/browsertest_util.h

+// Copyright (c) 2013 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_BROWSERTEST_UTIL_H_
+#define CHROME_BROWSER_EXTENSIONS_BROWSERTEST_UTIL_H_
+
+#include <string>
+
+class Profile;
+
+namespace extensions {
+namespace browsertest_util {
+
+// Waits until |script| calls "window.domAutomationController.send(result)",
+// where |result| is a string, and returns |result|. Fails the test and returns
+// an empty string if |extension_id| isn't installed in |profile| or doesn't
+// have a background page, or if executing the script fails.
+std::string ExecuteScriptInBackgroundPage(Profile* profile,
+                                          const std::string& extension_id,
+                                          const std::string& script);
+
+}  // namespace browsertest_util
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_BROWSERTEST_UTIL_H_