[OTS] Add support for the MATH table.

src/layout.h

 // 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.
 
 #ifndef OTS_LAYOUT_H_
 #define OTS_LAYOUT_H_
 
 #include "ots.h"
 
 // Utility functions for OpenType layout common table formats.
@@ skipping 26 matching lines @@
 bool ParseLookupListTable(OpenTypeFile *file, const uint8_t *data,
                           const size_t length,
                           const LookupSubtableParser* parser,
                           uint16_t* num_lookups);
 
 bool ParseClassDefTable(const uint8_t *data, size_t length,
                         const uint16_t num_glyphs,
                         const uint16_t num_classes);
 
 bool ParseCoverageTable(const uint8_t *data, size_t length,
-                        const uint16_t num_glyphs);
+                        const uint16_t num_glyphs,
+                        const uint16_t expected_num_glyphs = 0);
 
 bool ParseDeviceTable(const uint8_t *data, size_t length);
 
 // Parser for 'Contextual' subtable shared by GSUB/GPOS tables.
 bool ParseContextSubtable(const uint8_t *data, const size_t length,
                           const uint16_t num_glyphs,
                           const uint16_t num_lookups);
 
 // Parser for 'Chaining Contextual' subtable shared by GSUB/GPOS tables.
 bool ParseChainingContextSubtable(const uint8_t *data, const size_t length,
                                   const uint16_t num_glyphs,
                                   const uint16_t num_lookups);
 
 bool ParseExtensionSubtable(const OpenTypeFile *file,
                             const uint8_t *data, const size_t length,
                             const LookupSubtableParser* parser);
 
 }  // namespace ots
 
 #endif  // OTS_LAYOUT_H_