Respect SkColorSpace in SkPNGImageEncoder

This only changes behavior when the input SkBitmap/SkPixmap is
tagged with a non-null SkColorSpace.  Android tags their bitmaps
as sRGB when linear blending is enabled.  So this only changes
behavior in Android when linear blending is turned on.
*If linear blending is turned on, this will do a color correct
 encode (which is the desired behavior).
*If linear blending is turned off, this will do a legacy encode.

TODO: Add support for F16.
TODO: Add color space support to WEBP.
TODO: Tag encoded images with ICC profiles (when it makes sense).

BUG=skia:

Change-Id: Idd8a2836371d24a453d953e6fe2e76a87751be96
Reviewed-on: https://skia-review.googlesource.com/6498
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Matt Sarett <msarett@google.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/gm/encode-platform.cpp b/gm/encode-platform.cpp
index e8f420fb15..ca3cda1d73 100644
--- a/gm/encode-platform.cpp
+++ b/gm/encode-platform.cpp
@@ -70,7 +70,8 @@ static sk_sp<SkData> encode_data(SkEncodedImageFormat type, const SkBitmap& bitm
     #else
         switch (type) {
             case SkEncodedImageFormat::kPNG:
-                return SkEncodeImageAsPNG(&buf, src) ? buf.detachAsData() : nullptr;
+                return SkEncodeImageAsPNG(&buf, src, SkEncodeOptions()) ? buf.detachAsData()
+                                                                        : nullptr;
             case SkEncodedImageFormat::kJPEG:
                 return SkEncodeImageAsJPEG(&buf, src, 100) ? buf.detachAsData() : nullptr;
             case SkEncodedImageFormat::kWEBP: