Move Extension into extensions namespace

chrome/common/extensions/manifest_tests/extension_manifests_filebrowser_unittest.cc

 // 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/common/extensions/manifest_tests/extension_manifest_test.h"
 
 #include "base/string_number_conversions.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_error_utils.h"
 #include "chrome/common/extensions/extension_manifest_constants.h"
 #include "chrome/common/extensions/file_browser_handler.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+using extensions::Extension;
+
 namespace errors = extension_manifest_errors;
 
 TEST_F(ExtensionManifestTest, FileBrowserHandlers) {
   Testcase testcases[] = {
     Testcase("filebrowser_invalid_access_permission.json",
              ExtensionErrorUtils::FormatErrorMessage(
                  errors::kInvalidFileAccessValue, base::IntToString(1))),
     Testcase("filebrowser_invalid_access_permission_list.json",
              errors::kInvalidFileAccessList),
     Testcase("filebrowser_invalid_empty_access_permission_list.json",
@@ skipping 60 matching lines @@
 #if defined(FILE_MANAGER_EXTENSION)
   EXPECT_EQ("", error);
 #else
   EXPECT_EQ(std::string(errors::kInvalidChromeURLOverrides), error);
 #endif
 
   // Extensions of other types can't ovverride chrome://files/ URL.
   LoadAndExpectError("filebrowser_url_override.json",
                      errors::kInvalidChromeURLOverrides);
 }