OTS: Adds more layout common table supports....

include/ots-memory-stream.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_MEMORY_STREAM_H_
 #define OTS_MEMORY_STREAM_H_
 
 #include <cstring>
 #include <limits>
 
 #include "opentype-sanitiser.h"
 
 namespace ots {
 
 class MemoryStream : public OTSStream {
  public:
   MemoryStream(void *ptr, size_t length)
       : ptr_(ptr), length_(length), off_(0) {
   }
 
-  bool WriteRaw(const void *data, size_t length) {
+  virtual bool WriteRaw(const void *data, size_t length) {
     if ((off_ + length > length_) ||
         (length > std::numeric_limits<size_t>::max() - off_)) {
       return false;
     }
     std::memcpy(static_cast<char*>(ptr_) + off_, data, length);
     off_ += length;
     return true;
   }
 
-  bool Seek(off_t position) {
+  virtual bool Seek(off_t position) {
     if (position < 0) return false;
     if (static_cast<size_t>(position) > length_) return false;
     off_ = position;
     return true;
   }
 
-  off_t Tell() const {
+  virtual off_t Tell() const {
     return off_;
   }
 
  private:
   void* const ptr_;
   size_t length_;
   off_t off_;
 };
 
 class ExpandingMemoryStream : public OTSStream {
@@ skipping 47 matching lines @@
  private:
   void* ptr_;
   size_t length_;
   const size_t limit_;
   off_t off_;
 };
 
 }  // namespace ots
 
 #endif  // OTS_MEMORY_STREAM_H_