SupportsUserData and manifest handlers for Extension; use them for the Omnibox API.

chrome/common/extensions/manifest_handler.h

+// 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.
+
+#ifndef CHROME_COMMON_EXTENSIONS_MANIFEST_HANDLER_H_
+#define CHROME_COMMON_EXTENSIONS_MANIFEST_HANDLER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/string16.h"
+
+namespace base {
+class Value;
+}
+
+namespace extensions {
+
+class Extension;
+
+class ManifestHandler {
+  // Attempts to parse the manifest value.

[Matt Perry, 2012/12/07 01:22:59]

This comment seems to have wandered away from home.

[Yoyo Zhou, 2012/12/07 02:13:32]

Found its way back.

+  // Returns true on success or false on failure; if false, |error| will
+  // be set to a failure message.
+ public:
+  ManifestHandler();
+  virtual ~ManifestHandler();
+
+  virtual bool Parse(const base::Value* value,
+                     Extension* extension,
+                     string16* error) = 0;
+};
+
+// Associate |handler| with |key| in the manifest. Takes ownership of |handler|.
+// TODO(yoz): Decide how to handle dotted subkeys.
+// WARNING: Manifest handlers registered only in the browser process are not
+// available to renderers.
+void RegisterManifestHandler(const std::string& key, ManifestHandler* handler);

[Matt Perry, 2012/12/07 01:22:59]

Make these static methods of ManifestHandler?

[Yoyo Zhou, 2012/12/07 02:13:32]

Sure.

+
+// Get the manifest handler associated with |key|, or NULL
+// if there is none.
+ManifestHandler* GetManifestHandler(const std::string& key);
+
+// If the handler is not handling most of the keys, it may be
+// more efficient to have a list of keys to iterate over.
+// TODO(yoz): this isn't the long-term solution.
+std::vector<std::string> GetManifestHandlerKeys();
+
+}  // namespace extensions
+
+#endif  // CHROME_COMMON_EXTENSIONS_MANIFEST_HANDLER_H_