Reason: override code is under #if !BUILDFLAG(IS_MAC) in PaintFocusRing().
When white override moved from PaintFocusRing() to FocusRingColor(),
canvas also got white rings in dark mode. On white canvas, the ring disappears.
Keep FocusRingColor() renderer-driven (for canvas).
Apply white override only in PaintFocusRing() and only for
keyword-based default rings. Explicit author colors stay untouched.
On non-Mac in dark mode, PaintFocusRing() forced the inner ring to white.
Result: explicit outline-color (for example red) was ignored.
Tab to the buttons. In dark mode, the outline should be red.
CL 7555272 -- Use specified outline color for focus rings (abandoned)
CL 2644337 -- Use the system accent color for dark mode focus ring on Mac (merged)
TEST_F(OutlinePainterTest, FocusRingRespectsExplicitOutlineColorInDarkMode)
// explicit outline-color must not be overridden in dark mode.