Move the PolicyDomain and PolicyNamespace types to the policy component.

components/policy/core/common/policy_namespace.h

Index: components/policy/core/common/policy_namespace.h
diff --git a/components/policy/core/common/policy_namespace.h b/components/policy/core/common/policy_namespace.h
new file mode 100644
index 0000000000000000000000000000000000000000..4d8cf1cc0f78ff79b12578a2ef69ea7ca5ba00e5
--- /dev/null
+++ b/components/policy/core/common/policy_namespace.h
@@ -0,0 +1,49 @@
+// 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 <string>
+
+#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 POLICY_EXPORT 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.
+  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;
+
+  PolicyDomain domain;
+  std::string component_id;
+};
+
+}  // namespace policy
+
+#endif  // COMPONENTS_POLICY_CORE_COMMON_POLICY_NAMESPACE_H_