Adding png scanline decoding to kIndex8

dm/DMSrcSink.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "DMSrcSink.h"
 #include "SamplePipeControllers.h"
 #include "SkCommonFlags.h"
@@ skipping 121 matching lines @@
                 case SkImageGenerator::kIncompleteInput:
                     break;
                 case SkImageGenerator::kInvalidConversion:
                     return Error::Nonfatal("Incompatible colortype conversion");
                 default:
                     // Everything else is considered a failure.
                     return SkStringPrintf("Couldn't getPixels %s.", fPath.c_str());
             }
             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");
             }
             for (int y = 0; y < decodeInfo.height(); ++y) {
                 const SkImageGenerator::Result result = scanlineDecoder->getScanlines(
                         bitmap.getAddr(0, y), 1, 0);
                 switch (result) {
                     case SkImageGenerator::kSuccess:
                     case SkImageGenerator::kIncompleteInput:
                         break;
@@ skipping 566 matching lines @@
             canvas->drawPicture(pic);
             return "";
         }
         SkISize size() const override { return fSrc.size(); }
         Name name() const override { sk_throw(); return ""; }  // No one should be calling this.
     } proxy(src);
     return fSink->draw(proxy, bitmap, stream, log);
 }
 
 }  // namespace DM