Add scanline decoding to SkCodec.

dm/DMSrcSink.cpp

Index: dm/DMSrcSink.cpp
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index 5ca66c50e207c4809f41396e907d354d4d78a17d..3de6e06ed9428345b458dab00e536f070233c5f7 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -9,11 +9,12 @@
 #include "SkOSFile.h"
 #include "SkPictureRecorder.h"
 #include "SkRandom.h"
-#include "SkSVGCanvas.h"
+#include "SkScanlineDecoder.h"
 #include "SkStream.h"
+#include "SkSVGCanvas.h"
 #include "SkXMLWriter.h"
 
-DEFINE_bool(codec, false, "Use SkCodec instead of SkImageDecoder");
+DEFINE_bool(codec, true, "Use SkCodec instead of SkImageDecoder");
 
 namespace DM {
 
@@ -68,19 +69,29 @@ Error ImageSrc::draw(SkCanvas* canvas) const {
                                       info.width(), info.height());
             }
             SkAutoLockPixels alp(bitmap);
-            const SkImageGenerator::Result result = codec->getPixels(info, bitmap.getPixels(),
-                                                                     bitmap.rowBytes());
-            switch (result) {
-                case SkImageGenerator::kSuccess:
-                // We consider incomplete to be valid, since we should still decode what is
-                // available.
-                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());
+            SkAutoTDelete<SkScanlineDecoder> scanlineDecoder(codec->getScanlineDecoder(info));
+            if (NULL == scanlineDecoder) {
+                return Error::Nonfatal("Cannot use scanline decoder for all images");
+            }
+
+            for (int y = 0; y < info.height(); ++y) {
+                const SkImageGenerator::Result result =
+                        scanlineDecoder->getNextScanline(bitmap.getAddr(0, y));
+                switch (result) {
+                    case SkImageGenerator::kSuccess:
+                        // We consider incomplete to be valid, since we should still decode what is
+                        // available.
+                    case SkImageGenerator::kIncompleteInput:
+                        break;
+                    default:
+                        // Everything else is considered a failure.
+                        return SkStringPrintf("Couldn't getPixels %s.", fPath.c_str());
+                }
+            }
+
+            const SkImageGenerator::Result result = scanlineDecoder->finish();
+            if (result != SkImageGenerator::kSuccess) {
+                return SkStringPrintf("failed in finish!");
             }
         } else {
             if (!SkImageDecoder::DecodeMemory(encoded->data(), encoded->size(), &bitmap,