Fix color xforms for Index8 bmps

Thanks to Gold for catching this.

BUG=skia:4895

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4426

Change-Id: Icc816d933e9e2fd312858a5430fa21a47722563e
Reviewed-on: https://skia-review.googlesource.com/4426
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>

1 files changed, 2 insertions, 9 deletions

diff --git a/src/codec/SkPngCodec.cpp b/src/codec/SkPngCodec.cpp
index da6e062dac..a7359ee848 100644
--- a/src/codec/SkPngCodec.cpp
+++ b/src/codec/SkPngCodec.cpp
@@ -231,7 +231,7 @@ bool SkPngCodec::createColorTable(const SkImageInfo& dstInfo, int* ctableCount)
     if (png_get_tRNS(fPng_ptr, fInfo_ptr, &alphas, &numColorsWithAlpha, nullptr)) {
         // If we are performing a color xform, it will handle the premultiply.  Otherwise,
         // we'll do it here.
-        bool premultiply =  !this->colorXform() && needs_premul(dstInfo, this->getInfo());
+        bool premultiply = !this->colorXform() && needs_premul(dstInfo, this->getInfo());
 
         // Choose which function to use to create the color table. If the final destination's
         // colortype is unpremultiplied, the color table will store unpremultiplied colors.
@@ -267,9 +267,7 @@ bool SkPngCodec::createColorTable(const SkImageInfo& dstInfo, int* ctableCount)
     // If we are not decoding to F16, we can color xform now and store the results
     // in the color table.
     if (this->colorXform() && kRGBA_F16_SkColorType != dstInfo.colorType()) {
-        SkColorSpaceXform::ColorFormat xformColorFormat = is_rgba(dstInfo.colorType()) ?
-                SkColorSpaceXform::kRGBA_8888_ColorFormat :
-                SkColorSpaceXform::kBGRA_8888_ColorFormat;
+        SkColorSpaceXform::ColorFormat xformColorFormat = select_xform_format(dstInfo.colorType());
         SkAlphaType xformAlphaType = select_xform_alpha(dstInfo.alphaType(),
                                                         this->getInfo().alphaType());
         SkAssertResult(this->colorXform()->apply(xformColorFormat, colorTable,
@@ -1111,11 +1109,6 @@ void SkPngCodec::initializeXformParams() {
     }
 }
 
-static inline bool apply_xform_on_decode(SkColorType dstColorType, SkEncodedInfo::Color srcColor) {
-    // We will apply the color xform when reading the color table, unless F16 is requested.
-    return SkEncodedInfo::kPalette_Color != srcColor || kRGBA_F16_SkColorType == dstColorType;
-}
-
 void SkPngCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Options& options) {
     SkImageInfo swizzlerInfo = dstInfo;
     Options swizzlerOptions = options;