Add support for 'kern' OpenType table....

src/kern.h

+// Copyright (c) 2009 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 OTS_KERN_H_
+#define OTS_KERN_H_
+
+#include <vector>
+
+#include "ots.h"
+
+namespace ots {
+
+struct OpenTypeKERNFormat0Pair {
+  uint16_t left;
+  uint16_t right;
+  int16_t value;
+};
+
+struct OpenTypeKERNFormat0 {
+  uint16_t version;
+  uint16_t coverage;
+  uint16_t search_range;
+  uint16_t entry_selector;
+  uint16_t range_shift;
+  std::vector<OpenTypeKERNFormat0Pair> pairs;
+};
+
+// Format 2 is not supported. Since the format is not supported by Windows,
+// WebFonts unlikely use it. I've checked thousands of proprietary fonts and
+// free fonts, and found no font uses the format.
+
+struct OpenTypeKERN {
+  uint16_t version;
+  std::vector<OpenTypeKERNFormat0> subtables;
+};
+
+}  // namespace ots
+
+#endif  // OTS_KERN_H_