Try to improve toolbar separator coloration for themed browser windows.

chrome/browser/ui/views/frame/browser_view.cc

Index: chrome/browser/ui/views/frame/browser_view.cc
diff --git a/chrome/browser/ui/views/frame/browser_view.cc b/chrome/browser/ui/views/frame/browser_view.cc
index 489d9b147d471704af9c65a32e0ba2561b7d123b..77f020e543f8713b575d986679987b2b397e6d3f 100644
--- a/chrome/browser/ui/views/frame/browser_view.cc
+++ b/chrome/browser/ui/views/frame/browser_view.cc
@@ -221,18 +221,10 @@ void PaintDetachedBookmarkBar(gfx::Canvas* canvas,
       fill_rect,
       tp->GetColor(ThemeProperties::COLOR_DETACHED_BOOKMARK_BAR_BACKGROUND));
 
-  // Draw the separators above and below bookmark bar;
-  // if animating, these are fading in/out.
-  SkColor separator_color =
-      tp->GetColor(ThemeProperties::COLOR_DETACHED_BOOKMARK_BAR_SEPARATOR);

[Evan Stade, 2017/01/13 01:16:52]

This code looks weird because when the code was originally written, it drew a
separator at the top as well (where the luma wasn't touched). As part of MD,
that was changed to be drawn by the toolbar instead. Now there are two separate
color identifiers so the calculation can be done in ThemeService.

-
-  // For the bottom separator, increase the luminance. Either double it or halve
-  // the distance to 1.0, whichever is less of a difference.
-  color_utils::HSL hsl;
-  color_utils::SkColorToHSL(separator_color, &hsl);
-  hsl.l = std::min((hsl.l + 1) / 2, hsl.l * 2);
+  // Draw the separator below the detached bookmark bar.
   BrowserView::Paint1pxHorizontalLine(
-      canvas, color_utils::HSLToSkColor(hsl, SK_AlphaOPAQUE),
+      canvas,
+      tp->GetColor(ThemeProperties::COLOR_DETACHED_BOOKMARK_BAR_SEPARATOR),
       view->GetLocalBounds(), true);
 }