Simplify the situations in which subpixels are accumulated, so that it
is only done for translation or identity transformation matrices. Also,
apply accumulated subpixels to more operations in PaintContext. This
fixes several pre-existing reftests and hopefully will eliminate
off-by-one errors in flaky reftests.
Fixes#10881.
* [fix] Input line height and styling
* [new] Input line height ref test
* [fix] Test for input in manifest
* Updated CSS tests with new expected failures.