Fix a comment in the PolicyDomain enum definition

components/policy/core/common/policy_namespace.h

 // Copyright 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 COMPONENTS_POLICY_CORE_COMMON_POLICY_NAMESPACE_H_
 #define COMPONENTS_POLICY_CORE_COMMON_POLICY_NAMESPACE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <string>
 #include <vector>
 
 #include "base/containers/hash_tables.h"
 #include "components/policy/policy_export.h"
 
 namespace policy {
 
 // Policies are namespaced by a (PolicyDomain, ID) pair. The meaning of the ID
 // string depends on the domain; for example, if the PolicyDomain is
 // "extensions" then the ID identifies the extension that the policies control.
 enum PolicyDomain {
   // The component ID for chrome policies is always the empty string.
   POLICY_DOMAIN_CHROME,
 
-  // The extensions policy domain is a work in progress. Included here for
-  // tests.
+  // The component ID for the extension policies is equal to the extension ID.
   POLICY_DOMAIN_EXTENSIONS,
 
   // Must be the last entry.
   POLICY_DOMAIN_SIZE,
 };
 
 // Groups a policy domain and a component ID in a single object representing
 // a policy namespace. Objects of this class can be used as keys in std::maps.
 struct POLICY_EXPORT PolicyNamespace {
- public:
   PolicyNamespace();
   PolicyNamespace(PolicyDomain domain, const std::string& component_id);
   PolicyNamespace(const PolicyNamespace& other);
   ~PolicyNamespace();
 
   PolicyNamespace& operator=(const PolicyNamespace& other);
   bool operator<(const PolicyNamespace& other) const;
   bool operator==(const PolicyNamespace& other) const;
   bool operator!=(const PolicyNamespace& other) const;
 
@@ skipping 13 matching lines @@
 template <>
 struct hash<policy::PolicyNamespace> {
   std::size_t operator()(const policy::PolicyNamespace& ns) const {
     return hash<std::string>()(ns.component_id) ^ (UINT64_C(1) << ns.domain);
   }
 };
 
 }  // namespace BASE_HASH_NAMESPACE
 
 #endif  // COMPONENTS_POLICY_CORE_COMMON_POLICY_NAMESPACE_H_