Extract ResultCatcher from ExtensionApiTest. Use it in ShellApiTest.

extensions/shell/test/shell_apitest.h

+// Copyright 2014 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 EXTENSIONS_SHELL_TEST_SHELL_API_TEST_H_
+#define EXTENSIONS_SHELL_TEST_SHELL_API_TEST_H_
+
+#include <string>
+
+#include "extensions/shell/test/shell_test.h"
+
+namespace extensions {
+
+// Base class for app shell browser API tests that load an app/extension
+// and wait for a success message from the chrome.test API.
+class ShellApiTest : public AppShellTest {
+ public:
+  ShellApiTest();
+  virtual ~ShellApiTest();
+
+  // Loads an unpacked platform app from a directory using the current
+  // ExtensionSystem, launches it, and waits for a chrome.test success
+  // notification. Returns true if the test succeeds. |app_dir| is a
+  // subpath under extensions/test/data.
+  bool RunAppTest(const std::string& app_dir);
+
+ protected:
+  // If it failed, what was the error message?
+  std::string message_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ShellApiTest);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_SHELL_TEST_SHELL_API_TEST_H_