Only use JDCT_FAST if it is supported in jpeg.

src/images/SkImageDecoder_libjpeg.cpp

Index: src/images/SkImageDecoder_libjpeg.cpp
diff --git a/src/images/SkImageDecoder_libjpeg.cpp b/src/images/SkImageDecoder_libjpeg.cpp
index 4f32aa918614c8e72afd9cd4a7f59e5335ac3f62..67bca1f4ae8d9d38259a8b98e5d3f2ab24f679e7 100644
--- a/src/images/SkImageDecoder_libjpeg.cpp
+++ b/src/images/SkImageDecoder_libjpeg.cpp
@@ -268,11 +268,15 @@ bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {
     */
     int sampleSize = this->getSampleSize();
 
-    if (this->getPreferQualityOverSpeed()) {
-        cinfo.dct_method = JDCT_ISLOW;
-    } else {
+#ifdef DCT_IFAST_SUPPORTED
+    if (!this->getPreferQualityOverSpeed()) {
         cinfo.dct_method = JDCT_IFAST;
+    } else {
+#endif
+        cinfo.dct_method = JDCT_ISLOW;

[djsollen, 2013/04/12 15:51:51]

for readability I think it would be better to just duplicate this line in an
else statement.

[scroggo, 2013/04/12 15:57:01]

Done.

+#ifdef DCT_IFAST_SUPPORTED
     }
+#endif
 
     cinfo.scale_num = 1;
     cinfo.scale_denom = sampleSize;