Add SkCodec, including PNG implementation.

dm/DMSrcSink.cpp

Index: dm/DMSrcSink.cpp
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index b44f1d78180e94e9d9f5505789024e5db42c4007..47e2a9e1a115c6b24f1017b981a16149f6f48128 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -1,6 +1,7 @@
 #include "DMSrcSink.h"
 #include "SamplePipeControllers.h"
 #include "SkCommonFlags.h"
+#include "SkCodec.h"
 #include "SkDocument.h"
 #include "SkMultiPictureDraw.h"
 #include "SkNullCanvas.h"
@@ -11,6 +12,8 @@
 #include "SkStream.h"
 #include "SkXMLWriter.h"
 
+DEFINE_bool(codec, false, "Use SkCodec instead of SkImageDecoder");
+
 namespace DM {
 
 GMSrc::GMSrc(skiagm::GMRegistry::Factory factory) : fFactory(factory) {}
@@ -45,9 +48,35 @@ Error ImageSrc::draw(SkCanvas* canvas) const {
     if (fDivisor == 0) {
         // Decode the full image.
         SkBitmap bitmap;
-        if (!SkImageDecoder::DecodeMemory(encoded->data(), encoded->size(), &bitmap,
-                                          dstColorType, SkImageDecoder::kDecodePixels_Mode)) {
-            return SkStringPrintf("Couldn't decode %s.", fPath.c_str());
+        if (FLAGS_codec) {
+            SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(encoded));
+            if (!codec) {
+                return SkStringPrintf("Couldn't decode %s.", fPath.c_str());
+            }
+            SkImageInfo info;
+            if (!codec->getInfo(&info)) {
+                return SkStringPrintf("Couldn't getInfo %s.", fPath.c_str());
+            }
+            info = info.makeColorType(dstColorType);
+            if (info.alphaType() == kUnpremul_SkAlphaType) {
+                // FIXME: Currently we cannot draw unpremultiplied sources.
+                info = info.makeAlphaType(kPremul_SkAlphaType);
+            }
+            if (!bitmap.tryAllocPixels(info)) {
+                return SkStringPrintf("Image(%s) is too large (%d x %d)\n", fPath.c_str(),
+                                      info.width(), info.height());
+            }
+            SkAutoLockPixels alp(bitmap);
+            const SkImageGenerator::Result result = codec->getPixels(info, bitmap.getPixels(),
+                                                                     bitmap.rowBytes());
+            if (result != SkImageGenerator::kSuccess) {
+                return SkStringPrintf("Couldn't getPixels %s.", fPath.c_str());
+            }
+        } else {
+            if (!SkImageDecoder::DecodeMemory(encoded->data(), encoded->size(), &bitmap,
+                                              dstColorType, SkImageDecoder::kDecodePixels_Mode)) {
+                return SkStringPrintf("Couldn't decode %s.", fPath.c_str());
+            }
         }
         encoded.reset((SkData*)NULL);  // Might as well drop this when we're done with it.
         canvas->drawBitmap(bitmap, 0,0);