Ship text-decoration-thickness, text-underline-offset

Ship text-decoration-thickness, text-underline-offset and from-font
keyword for text-underline-position.

Intent-to-ship approved in
https://groups.google.com/a/chromium.org/g/blink-dev/c/9OzS90KISXI/m/q5KYyyWBCAAJ

In collaboration with schenney@ for resolving blocking paint
invalidation issues and important refactorings in the paint code.
Big thanks!

Bug: 785230
Change-Id: I235a8e01fef8d8e9c4abd921190ce0023cf5bc16
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2440615Reviewed-by: Stephen Chenney <schenney@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812315}

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1907,7 +1907,7 @@
     },
     {
       name: "UnderlineOffsetThickness",
-      status: "test",
+      status: "stable",
     },
     {
       name: "UnoptimizedImagePolicies",

third_party/blink/web_tests/virtual/stable/webexposed/css-properties-as-js-properties-expected.txt

@@ -362,6 +362,7 @@ textDecorationColor
 textDecorationLine
 textDecorationSkipInk
 textDecorationStyle
+textDecorationThickness
 textIndent
 textOrientation
 textOverflow
@@ -369,6 +370,7 @@ textRendering
 textShadow
 textSizeAdjust
 textTransform
+textUnderlineOffset
 textUnderlinePosition
 top
 touchAction

third_party/blink/web_tests/virtual/stable/webexposed/css-property-listing-expected.txt

@@ -327,6 +327,7 @@ All changes to this list should go through Blink's feature review process: http:
     text-decoration-line
     text-decoration-skip-ink
     text-decoration-style
+    text-decoration-thickness
     text-indent
     text-orientation
     text-overflow
@@ -334,6 +335,7 @@ All changes to this list should go through Blink's feature review process: http:
     text-shadow
     text-size-adjust
     text-transform
+    text-underline-offset
     text-underline-position
     top
     touch-action
@@ -691,6 +693,7 @@ All changes to this list should go through Blink's feature review process: http:
         text-decoration-color
         text-decoration-line
         text-decoration-style
+        text-decoration-thickness
     transition
         transition-delay
         transition-duration