Fix errors caused by unsafe conversions to/from size_t

third_party/WebKit/Source/core/xml/parser/SharedBufferReader.cpp

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 31 matching lines @@
 SharedBufferReader::SharedBufferReader(PassRefPtr<SharedBuffer> buffer)
     : m_buffer(buffer)
     , m_currentOffset(0)
 {
 }
 
 SharedBufferReader::~SharedBufferReader()
 {
 }
 
-int SharedBufferReader::readData(char* outputBuffer, unsigned askedToRead)
+int SharedBufferReader::readData(char* outputBuffer, int askedToRead)
 {
     if (!m_buffer || m_currentOffset > m_buffer->size())
         return 0;
 
-    unsigned bytesCopied = 0;
-    unsigned bytesLeft = m_buffer->size() - m_currentOffset;
-    unsigned lenToCopy = std::min(askedToRead, bytesLeft);
+    size_t bytesCopied = 0;
+    size_t bytesLeft = m_buffer->size() - m_currentOffset;
+    size_t lenToCopy = std::min(safeCast<size_t>(askedToRead), bytesLeft);
 
     while (bytesCopied < lenToCopy) {
         const char* data;
-        unsigned segmentSize = m_buffer->getSomeData(data, m_currentOffset);
+        size_t segmentSize = m_buffer->getSomeData(data, m_currentOffset);
         if (!segmentSize)
             break;
 
         segmentSize = std::min(segmentSize, lenToCopy - bytesCopied);
         memcpy(outputBuffer + bytesCopied, data, segmentSize);
         bytesCopied += segmentSize;
         m_currentOffset += segmentSize;
     }
 
-    return bytesCopied;
+    return safeCast<int>(bytesCopied);
 }
 
 } // namespace blink