Adding png scanline decoding to kIndex8

dm/DMSrcSink.cpp

Index: dm/DMSrcSink.cpp
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index 6b3ec9749e7e22a2db3c7b46a9c154780ccc9abe..9811f9e4268ee7eb95014d6a67fea09faa700583 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -139,7 +139,8 @@ Error CodecSrc::draw(SkCanvas* canvas) const {
             }
             break;
         case kScanline_Mode: {
-            SkScanlineDecoder* scanlineDecoder = codec->getScanlineDecoder(decodeInfo);
+            SkScanlineDecoder* scanlineDecoder = codec->getScanlineDecoder(decodeInfo, NULL,
+                    colorPtr, colorCountPtr);
             if (NULL == scanlineDecoder) {
                 return Error::Nonfatal("Cannot use scanline decoder for all images");
             }