Improve painting of cros tray separators.

ui/gfx/canvas.cc

Index: ui/gfx/canvas.cc
diff --git a/ui/gfx/canvas.cc b/ui/gfx/canvas.cc
index ed9cea122815fb411d68469ee87438dfd8ab3131..2b430afb0b89e6aaea6a7648c90b43c4f488ac5f 100644
--- a/ui/gfx/canvas.cc
+++ b/ui/gfx/canvas.cc
@@ -334,6 +334,15 @@ void Canvas::DrawSharpLine(PointF p1, PointF p2, SkColor color) {
   DrawLine(p1, p2, flags);
 }
 
+void Canvas::Draw1pxLine(PointF p1, PointF p2, SkColor color) {
+  ScopedCanvas scoped(this);
+  float dsf = UndoDeviceScaleFactor();
+  p1.Scale(dsf);
+  p2.Scale(dsf);
+
+  DrawLine(p1, p2, color);
+}
+
 void Canvas::DrawCircle(const Point& center_point,
                         int radius,
                         const cc::PaintFlags& flags) {