Add an experimental permissions API for extensions.

chrome/browser/extensions/extension_permissions_api_constants.h

Index: chrome/browser/extensions/extension_permissions_api_constants.h
diff --git a/chrome/browser/extensions/extension_permissions_api_constants.h b/chrome/browser/extensions/extension_permissions_api_constants.h
new file mode 100644
index 0000000000000000000000000000000000000000..64b51162d3b7a565126cff2530bd03409c30dbfd
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+++ b/chrome/browser/extensions/extension_permissions_api_constants.h
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+// Copyright (c) 2011 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.
+
+// Constants used for the Tabs API and the Windows API.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_PERMISSIONS_API_CONSTANTS_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_PERMISSIONS_API_CONSTANTS_H_
+#pragma once
+
+namespace extension_permissions_module_constants {
+
+// Keys used in serializing permissions data and events.
+extern const char kApisKey[];
+
+// Error messages.
+extern const char kCantRemoveRequiredPermissionsError[];
+extern const char kNotInOptionalPermissionsError[];
+extern const char kNotWhitelistedError[];
+extern const char kUnknownPermissionError[];
+
+// Event names.
+extern const char kOnAdded[];
+extern const char kOnRemoved[];
+
+};  // namespace extension_permissions_module_constants
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_PERMISSIONS_API_CONSTANTS_H_