Extract permission alias info from PermissionsProvider

extensions/common/alias.h

Index: extensions/common/alias.h
diff --git a/extensions/common/alias.h b/extensions/common/alias.h
new file mode 100644
index 0000000000000000000000000000000000000000..f1219918322b551551a2dd7ef401c31702493be8
--- /dev/null
+++ b/extensions/common/alias.h
@@ -0,0 +1,41 @@
+// Copyright 2016 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_COMMON_ALIAS_H_
+#define EXTENSIONS_COMMON_ALIAS_H_
+
+#include <string>
+
+namespace extensions {
+
+// Information about a specific alias.
+class Alias {
+ public:
+  // |name|: The alias name.
+  // |real_name|: The real name behind alias.
+  // |upper_version_bound|: Upper (non-inclusive) bound on Chrome versions for
+  //     which the alias is valid. For version past this one, alias should be
+  //     ignored. NULL for aliases without version restriction.
+  explicit Alias(const char* const name,
+                 const char* const real_name,
+                 const char* const upper_version_bound);
+  ~Alias();
+
+  const std::string& name() const { return name_; }
+  const std::string& real_name() const { return real_name_; }
+  bool valid() const { return valid_; }
+
+ private:
+  // The alias name.
+  std::string name_;
+  // The real name behind the alias.
+  std::string real_name_;
+  // Whether the alias is valid - the alias validity might be restricted by
+  // current version.
+  bool valid_;
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_COMMON_ALIAS_H_