Implement Fill() for incomplete decodes to RGBA_F16

include/codec/SkCodec.h

Index: include/codec/SkCodec.h
diff --git a/include/codec/SkCodec.h b/include/codec/SkCodec.h
index bee4f3c9107ec7c749c6a6033766351a51171960..b0647edc6fef946cfabe1588d990acc4f010c552 100644
--- a/include/codec/SkCodec.h
+++ b/include/codec/SkCodec.h
@@ -601,30 +601,30 @@ protected:
      * On an incomplete input, getPixels() and getScanlines() will fill any uninitialized
      * scanlines.  This allows the subclass to indicate what value to fill with.
      *
-     * @param colorType Destination color type.
+     * @param dstInfo   Describes the destination.
      * @return          The value with which to fill uninitialized pixels.
      *
-     * Note that we can interpret the return value as an SkPMColor, a 16-bit 565 color,
-     * an 8-bit gray color, or an 8-bit index into a color table, depending on the color
-     * type.
+     * Note that we can interpret the return value as a 64-bit Float16 color, a SkPMColor,
+     * a 16-bit 565 color, an 8-bit gray color, or an 8-bit index into a color table,
+     * depending on the color type.
      */
-    uint32_t getFillValue(SkColorType colorType) const {
-        return this->onGetFillValue(colorType);
+    uint64_t getFillValue(const SkImageInfo& dstInfo) const {
+        return this->onGetFillValue(dstInfo);
     }
 
     /**
      * Some subclasses will override this function, but this is a useful default for the color
-     * types that we support.  Note that for color types that do not use the full 32-bits,
+     * types that we support.  Note that for color types that do not use the full 64-bits,
      * we will simply take the low bits of the fill value.
      *
+     * The defaults are:
+     * kRGBA_F16_SkColorType: Transparent or Black, depending on the src alpha type
      * kN32_SkColorType: Transparent or Black, depending on the src alpha type
      * kRGB_565_SkColorType: Black
      * kGray_8_SkColorType: Black
      * kIndex_8_SkColorType: First color in color table
      */
-    virtual uint32_t onGetFillValue(SkColorType /*colorType*/) const {
-        return kOpaque_SkAlphaType == fSrcInfo.alphaType() ? SK_ColorBLACK : SK_ColorTRANSPARENT;
-    }
+    virtual uint64_t onGetFillValue(const SkImageInfo& dstInfo) const;
 
     /**
      * Get method for the input stream