Add an SkImageGeneratorCG

src/codec/SkCodecImageGenerator.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 "SkCodecImageGenerator.h"
 
 SkImageGenerator* SkCodecImageGenerator::NewFromEncodedCodec(SkData* data) {
     SkCodec* codec = SkCodec::NewFromData(data);
     if (nullptr == codec) {
         return nullptr;
     }
 
     return new SkCodecImageGenerator(codec, data);
 }
 
-static SkImageInfo make_premul(const SkImageInfo& info) {
-    if (kUnpremul_SkAlphaType == info.alphaType()) {
-        return info.makeAlphaType(kPremul_SkAlphaType);
-    }
-
-    return info;
-}
-
 SkCodecImageGenerator::SkCodecImageGenerator(SkCodec* codec, SkData* data)
-    : INHERITED(make_premul(codec->getInfo()))
+    : INHERITED(codec->getInfo())
     , fCodec(codec)
     , fData(SkRef(data))
     , fYWidth(0)
     , fUWidth(0)
     , fVWidth(0)
 {}
 
 SkData* SkCodecImageGenerator::onRefEncodedData(SK_REFENCODEDDATA_CTXPARAM) {
     return SkRef(fData.get());
 }
@@ skipping 55 matching lines @@
     }
 
     switch (result) {
         case SkCodec::kSuccess:
         case SkCodec::kIncompleteInput:
             return true;
         default:
             return false;
     }
 }