Add GDEF support.

Adds src/gdef.{h,cc} for GDEF table support.
This CL also adds src/layout.{h,cc} that implement utility functions for OpenType layout common table formats.

BUG=27131
TEST=ran test_{,un}malicious_fonts.sh for 4500+ OpenType fonts.


git-svn-id: http://ots.googlecode.com/svn/trunk@49 a4e77c2c-9104-11de-800e-5b313e0d2bf3
diff --git a/src/gdef.h b/src/gdef.h
new file mode 100644
index 0000000..5ee06d7
--- /dev/null
+++ b/src/gdef.h
@@ -0,0 +1,27 @@
+// 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_GDEF_H_
+#define OTS_GDEF_H_
+
+#include "ots.h"
+
+namespace ots {
+
+struct OpenTypeGDEF {
+  OpenTypeGDEF()
+      : version_2(false),
+        data(NULL),
+        length(0) {
+  }
+
+  bool version_2;
+  const uint8_t *data;
+  size_t length;
+};
+
+}  // namespace ots
+
+#endif
+