Add scanline decoding to SkCodec.

dm/DMSrcSink.cpp

Index: dm/DMSrcSink.cpp
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index 638f6708343ec6c8b24dcb5d35cde124cbfc5452..29c6800505026254c18d403a6f4b595c1d265db3 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -10,8 +10,9 @@
 #include "SkPictureData.h"
 #include "SkPictureRecorder.h"
 #include "SkRandom.h"
-#include "SkSVGCanvas.h"
+#include "SkScanlineDecoder.h"
 #include "SkStream.h"
+#include "SkSVGCanvas.h"
 #include "SkXMLWriter.h"
 
 namespace DM {
@@ -70,19 +71,32 @@ Error CodecSrc::draw(SkCanvas* canvas) const {
     }
 
     SkAutoLockPixels alp(bitmap);
-    switch (codec->getPixels(decodeInfo, bitmap.getPixels(), bitmap.rowBytes())) {
-        case SkImageGenerator::kSuccess:
-        // We consider incomplete to be valid, since we should still decode what is
-        // available.
-        case SkImageGenerator::kIncompleteInput:
-            canvas->drawBitmap(bitmap, 0, 0);
-            return "";
-        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());
+    SkScanlineDecoder* scanlineDecoder = codec->getScanlineDecoder(decodeInfo);
+    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:
+                // 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!");
+    }
+    canvas->drawBitmap(bitmap, 0, 0);
+    return "";
 }
 
 SkISize CodecSrc::size() const {