Web test crash with CSSSystemColorComputeToSelf enabled

virtual/forced-high-contrast-colors/fast/css/forced-colors-mode/forced-colors-mode-13.html
was crashing with CSSSystemColorComputeToSelf enabled. The reason
being that CSSColorInterpolationType::CreateInterpolableColor() didn't
properly handle system colors with the flag enabled.

Bug: 1081945,970285
Change-Id: I83b742ef2675addf9129187eb9cfa7c5faaa8aee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2404109Reviewed-by: Kevin Babbitt <kbabbitt@microsoft.com>
Reviewed-by: Fredrik Söderquist <fs@opera.com>
Commit-Queue: Alison Maher <almaher@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#806336}

third_party/blink/renderer/core/animation/css_color_interpolation_type.cc

@@ -79,8 +79,8 @@ CSSColorInterpolationType::CreateInterpolableColor(CSSValueID keyword) {
 
 std::unique_ptr<InterpolableValue>
 CSSColorInterpolationType::CreateInterpolableColor(const StyleColor& color) {
-  if (color.IsCurrentColor())
-    return CreateInterpolableColorForIndex(kCurrentcolor);
+  if (!color.IsNumeric())
+    return CreateInterpolableColor(color.GetColorKeyword());
   return CreateInterpolableColor(color.GetColor());
 }
 

third_party/blink/renderer/core/css/style_color.h

@@ -66,6 +66,10 @@ class CORE_EXPORT StyleColor {
     DCHECK(IsNumeric());
     return color_;
   }
+  CSSValueID GetColorKeyword() const {
+    DCHECK(!IsNumeric());
+    return color_keyword_;
+  }
 
   Color Resolve(Color current_color, WebColorScheme color_scheme) const;
 

third_party/blink/web_tests/TestExpectations

@@ -5745,8 +5745,6 @@ crbug.com/970285 [ Win ] virtual/forced-high-contrast-colors/* [ Pass ]
 crbug.com/970285 [ Linux ] virtual/forced-high-contrast-colors/* [ Pass ]
 crbug.com/970285 [ Android ] virtual/forced-high-contrast-colors/* [ Pass ]
 
-crbug.com/1081945 virtual/forced-high-contrast-colors/fast/css/forced-colors-mode/forced-colors-mode-13.html [ Crash ]
-
 # Expected failures for dark mode tests when the corresponding flags
 # are not enabled.
 crbug.com/1090660 external/wpt/css/css-color-adjust/rendering/dark-color-scheme/svg-as-image.html [ Skip ]