Move Extension into extensions namespace

chrome/common/extensions/manifest_tests/extension_manifests_chromepermission_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 "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_manifest_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace errors = extension_manifest_errors;
 
 TEST_F(ExtensionManifestTest, ChromeURLPermissionInvalid) {
   LoadAndExpectError("permission_chrome_url_invalid.json",
                      errors::kInvalidPermissionScheme);
 }
 
 TEST_F(ExtensionManifestTest, ChromeResourcesPermissionValidOnlyForComponents) {
   LoadAndExpectError("permission_chrome_resources_url.json",
                      errors::kInvalidPermissionScheme);
   std::string error;
   LoadExtension(Manifest("permission_chrome_resources_url.json"),
                 &error,
-                Extension::COMPONENT,
-                Extension::STRICT_ERROR_CHECKS);
+                extensions::Extension::COMPONENT,
+                extensions::Extension::STRICT_ERROR_CHECKS);
   EXPECT_EQ("", error);
 }