This reverts commit 2d9155e1.

Fixes a regression with semitransparent images (flutter/flutter#11169)

* Revert "Revert "Reland "Run Flutter on iOS and Android with color correct Skia" (#3818)" (#3823)"

This reverts commit db8d8a99.

* Fix test code to match internal API change

This reverts commit 2650f529.

* Revert "Revert "Run Flutter on iOS and Android with color correct Skia (#3743)" (#3775)"

This reverts commit cfe70e07.

* Enable sRGB on IO thread, too

* Add 4444 as a fallback rendering mode

* Use bare ptr to SkColorSpace (not sk_sp) in PrerollContext

This reverts commit ffe8181f.

* Run Flutter on iOS and Android with color correct Skia (#3716)

***Turns on color correct rendering for Android and iOS
***Communicates dst color space to raster cache
***Turns on color space aware image decoding

Test:
***color_testing_demo on Pixel XL
***flutter_gallery on iPad Mini and iPad Pro (haven't figured out how to run manual_tests on iOS)

TODO:
I needed to split up this CL somewhere. These are follow-up tasks.
***Make desktop backends color correct
***Make debugging tools (ex: encoding frames to png) preserve color space
***Investigate using UIKit API to allow iOS to fine tune color space of rendered content

***Turns on color correct rendering for Android and iOS
***Communicates dst color space to raster cache
***Turns on color space aware image decoding

Test:
***color_testing_demo on Pixel XL
***flutter_gallery on iPad Mini and iPad Pro (haven't figured out how to run manual_tests on iOS)

TODO:
I needed to split up this CL somewhere. These are follow-up tasks.
***Make desktop backends color correct
***Make debugging tools (ex: encoding frames to png) preserve color space
***Investigate using UIKit API to allow iOS to fine tune color space of rendered content