[AspectRatio] Ship aspect-ratio

Intent to ship:
https://groups.google.com/a/chromium.org/g/blink-dev/c/TF41VMfLhMI

R=ikilpatrick@chromium.org, mstensho@chromium.org

Bug: 1045668
Change-Id: I3d310b9e3739694af769619ca14f8563fcaea312
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2485582
Auto-Submit: Christian Biesinger <cbiesinger@chromium.org>
Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Reviewed-by: Manuel Rego <rego@igalia.com>
Commit-Queue: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818930}

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -425,7 +425,7 @@
     },
     {
       name: "CSSAspectRatioProperty",
-      status: "experimental",
+      status: "stable",
     },
     {
       name: "CSSCalcAsInt",

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

@@ -17,6 +17,7 @@ animationPlayState
 animationTimingFunction
 appearance
 ascentOverride
+aspectRatio
 backdropFilter
 backfaceVisibility
 background

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

@@ -70,6 +70,7 @@ All changes to this list should go through Blink's feature review process: http:
     animation-play-state
     animation-timing-function
     appearance
+    aspect-ratio
     backdrop-filter
     backface-visibility
     background-attachment