Bug 564410 - Use png_set_filter to make system libpng not use write filters. r=glennrp

modules/libpr0n/encoders/png/nsPNGEncoder.cpp

@@ -272,6 +272,10 @@ NS_IMETHODIMP nsPNGEncoder::AddImageFrame(const PRUint8* aData,
     return NS_ERROR_INVALID_ARG;
   }
 
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+  png_set_filter(mPNG, PNG_FILTER_TYPE_BASE, PNG_FILTER_VALUE_NONE);
+#endif
+
   // write each row: if we add more input formats, we may want to
   // generalize the conversions
   if (aInputFormat == INPUT_FORMAT_HOSTARGB) {