Support more swizzles to 565 in SkCodec
Add more swizzling functions for swizzling to 565. Much of this
code was revived from crrev.com/1055743003 (for BMP). Also added
swizzling functions for WBMP.
Consolidate the static function conversion_possible.
In SkCodec::getPixels, check that the alphatype corresponds to the
colorType. This prevents requesting 565 + non-opaque.
In SkIcoCodec, report that the image is unpremul (instead of
whatever the largest embedded codec thinks), but modify the
requested info to have the alpha type expected/required by the
embedded codec.
Add tests for decoding to 565.
BUG=skia:3257
BUG=skia:3683
Review URL: https://codereview.chromium.org/1277213002
16 files changed