Create an SkCodecImageGenerator

src/codec/SkCodecImageGenerator.h

+/*
+ * 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 "SkCodec.h"
+#include "SkData.h"
+#include "SkImageGenerator.h"
+
+class SkCodecImageGenerator : public SkImageGenerator {
+public:
+    /*
+     * If this data represents an encoded image that we know how to decode,
+     * return an SkCodecImageGenerator.  Otherwise return nullptr.
+     *
+     * Refs the data if an image generator can be returned.  Otherwise does
+     * not affect the data.
+     */
+    static SkImageGenerator* NewFromEncodedCodec(SkData* data);
+
+protected:
+    SkData* onRefEncodedData(SK_REFENCODEDDATA_CTXPARAM) override;
+
+    bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, SkPMColor ctable[],
+            int* ctableCount) override;
+
+    bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
+            SkYUVColorSpace* colorSpace) override;
+
+private:
+    /*
+     * Takes ownership of codec
+     * Refs the data
+     */
+    SkCodecImageGenerator(SkCodec* codec, SkData* data);
+
+    SkAutoTDelete<SkCodec> fCodec;
+    SkAutoTUnref<SkData> fData;
+
+    typedef SkImageGenerator INHERITED;
+};