Removing a bunch of unused platform code.

Source/WebCore/platform/image-decoders/png/PNGImageDecoder.cpp

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  * Copyright (C) 2007-2009 Torch Mobile, Inc.
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * Portions are Copyright (C) 2001 mozilla.org
  *
  * Other contributors:
  *   Stuart Parmenter <stuart@mozilla.com>
  *
@@ skipping 48 matching lines @@
 
 // Gamma constants.
 const double cMaxGamma = 21474.83;
 const double cDefaultGamma = 2.2;
 const double cInverseGamma = 0.45455;
 
 // Protect against large PNGs. See Mozilla's bug #251381 for more info.
 const unsigned long cMaxPNGSize = 1000000UL;
 
 // Called if the decoding of the image fails.
-#if PLATFORM(QT)
-static void PNGAPI decodingFailed(png_structp, png_const_charp) NO_RETURN;
-#endif
 static void PNGAPI decodingFailed(png_structp png, png_const_charp)
 {
     longjmp(JMPBUF(png), 1);
 }
 
 // Callbacks given to the read struct.  The first is for warnings (we want to
 // treat a particular warning as an error, which is why we have to register this
 // callback).
 static void PNGAPI decodingWarning(png_structp png, png_const_charp warningMsg)
 {
@@ skipping 460 matching lines @@
     // has failed.
     if (!m_reader->decode(*m_data, onlySize) && isAllDataReceived())
         setFailed();
     // If we're done decoding the image, we don't need the PNGImageReader
     // anymore.  (If we failed, |m_reader| has already been cleared.)
     else if (isComplete())
         m_reader.clear();
 }
 
 } // namespace WebCore