Refactor PDF ChunkStream and DocumentLoader code.

pdf/chunk_stream.h

 // 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 PDF_CHUNK_STREAM_H_
 #define PDF_CHUNK_STREAM_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 23 matching lines @@
                        std::vector<std::pair<size_t, size_t>>* ranges) const;
   bool IsRangeAvailable(size_t offset, size_t size) const;
   size_t GetFirstMissingByte() const;
 
   // Finds the first byte of the missing byte interval that offset belongs to.
   size_t GetFirstMissingByteInInterval(size_t offset) const;
   // Returns the last byte of the missing byte interval that offset belongs to.
   size_t GetLastMissingByteInInterval(size_t offset) const;
 
  private:
+  std::map<size_t, size_t>::const_iterator GetStartChunk(size_t offset) const;
+
   std::vector<unsigned char> data_;
 
-  // Pair, first - begining of the chunk, second - size of the chunk.
+  // Key: offset of the chunk.
+  // Value: size of the chunk.
   std::map<size_t, size_t> chunks_;
 
   size_t stream_size_;
 };
 
 };  // namespace chrome_pdf
 
 #endif  // PDF_CHUNK_STREAM_H_