Lands http://codereview.chromium.org/3153008 for bryeung:

base/keyboard_code_conversion.h

Index: base/keyboard_code_conversion.h
diff --git a/base/keyboard_code_conversion.h b/base/keyboard_code_conversion.h
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+// Copyright (c) 2010 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 BASE_KEYBOARD_CODE_CONVERSION_H_
+#define BASE_KEYBOARD_CODE_CONVERSION_H_
+#pragma once
+
+#include "base/keyboard_codes.h"
+
+#include <string>
+
+namespace base {
+
+// Convert a KeyIdentifer (see Section 6.3.3 here:
+// http://www.w3.org/TR/DOM-Level-3-Events/#keyset-keyidentifiers)
+// to a base::KeyboardCode.
+KeyboardCode KeyCodeFromKeyIdentifier(const std::string& key_identifier);
+
+}  // namespace
+
+#endif  // BASE_KEYBOARD_CODE_CONVERSION_H_