Route Dark Mode Windows Colors through GetAuraColor()

Win32 system colors currently don't support Dark Mode. As a result,
fallback on the Aura colors. Inverted color schemes can be ignored here
as it's only true when Chrome is running on a high-contrast AND when
the relative luminance of COLOR_WINDOWTEXT is greater than COLOR_WINDOW
(e.g. white on black), which is basically like dark mode.

BUG=928378

Change-Id: I71ae0c1dd13213278461c04f50ae8ae8e5599a87
Reviewed-on: https://chromium-review.googlesource.com/c/1455646
Commit-Queue: Robert Liao <[email protected]>
Auto-Submit: Robert Liao <[email protected]>
Reviewed-by: Peter Kasting <[email protected]>
Cr-Commit-Position: refs/heads/master@{#629610}

Author: Robert Liao

ui/native_theme/native_theme_win.cc

@@ -432,6 +432,14 @@ void NativeThemeWin::PaintDirect(SkCanvas* destination_canvas,
 }
 
 SkColor NativeThemeWin::GetSystemColor(ColorId color_id) const {
+  // Win32 system colors currently don't support Dark Mode. As a result,
+  // fallback on the Aura colors. Inverted color schemes can be ignored here
+  // as it's only true when Chrome is running on a high-contrast AND when the
+  // relative luminance of COLOR_WINDOWTEXT is greater than COLOR_WINDOW (e.g.
+  // white on black), which is basically like dark mode.
+  if (SystemDarkModeEnabled())
+    return GetAuraColor(color_id, this);
+
   // TODO: Obtain the correct colors for these using GetSysColor.
   // Button:
   constexpr SkColor kButtonHoverColor = SkColorSetRGB(6, 45, 117);