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 |extension_system_|

[James Cook, 2014/09/03 18:08:41]

maybe AppShellTest::extension_system_ since it isn't a member here? Or just say
something about the current ExtensionSystem?

[Yoyo Zhou, 2014/09/04 21:57:42]

Updated this.

+  // and attempts to launch it. Returns true on success.
+  // |app_dir| is a subpath under extensions/test/data.

[James Cook, 2014/09/03 18:08:41]

nit: wrap with line above

[Yoyo Zhou, 2014/09/04 21:57:42]

Done.

+  bool RunAppTest(const std::string& app_dir);
+
+ protected:
+  // If it failed, what was the error message?
+  std::string message_;
+

[James Cook, 2014/09/03 18:08:41]

DISALLOW_COPY_AND_ASSIGN

[Yoyo Zhou, 2014/09/04 21:57:42]

Done.

+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_SHELL_TEST_SHELL_API_TEST_H_