Only use JDCT_FAST if it is supported in jpeg.

src/images/SkImageDecoder_libjpeg.cpp

 
 /*
  * Copyright 2007 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkImageDecoder.h"
@@ skipping 250 matching lines @@
     if (status != JPEG_HEADER_OK) {
         return return_false(cinfo, *bm, "read_header");
     }
 
     /*  Try to fulfill the requested sampleSize. Since jpeg can do it (when it
         can) much faster that we, just use their num/denom api to approximate
         the size.
     */
     int sampleSize = this->getSampleSize();
 
+#ifdef DCT_IFAST_SUPPORTED
     if (this->getPreferQualityOverSpeed()) {
         cinfo.dct_method = JDCT_ISLOW;
     } else {
         cinfo.dct_method = JDCT_IFAST;
     }
+#else
+    cinfo.dct_method = JDCT_ISLOW;
+#endif
 
     cinfo.scale_num = 1;
     cinfo.scale_denom = sampleSize;
 
     /* this gives about 30% performance improvement. In theory it may
        reduce the visual quality, in practice I'm not seeing a difference
      */
     cinfo.do_fancy_upsampling = 0;
 
     /* this gives another few percents */
@@ skipping 724 matching lines @@
     return SkNEW(SkJPEGImageDecoder);
 }
 
 static SkImageEncoder* sk_libjpeg_efactory(SkImageEncoder::Type t) {
     return (SkImageEncoder::kJPEG_Type == t) ? SkNEW(SkJPEGImageEncoder) : NULL;
 }
 
 
 static SkTRegistry<SkImageDecoder*, SkStream*> gDReg(sk_libjpeg_dfactory);
 static SkTRegistry<SkImageEncoder*, SkImageEncoder::Type> gEReg(sk_libjpeg_efactory);