[Chrome OS] Fix the broken focus rectangle on Launcher icon.

ash/common/shelf/app_list_button.cc

Index: ash/common/shelf/app_list_button.cc
diff --git a/ash/common/shelf/app_list_button.cc b/ash/common/shelf/app_list_button.cc
index 6ab78cb246c04535783e5dc261b71ffee39e1681..18c545003cea34b2b3c663a3940bce3c4ccac235 100644
--- a/ash/common/shelf/app_list_button.cc
+++ b/ash/common/shelf/app_list_button.cc
@@ -169,20 +169,15 @@ void AppListButton::PaintMd(gfx::Canvas* canvas) {
   bg_paint.setStyle(SkPaint::kFill_Style);
   canvas->DrawCircle(circle_center, kAppListButtonRadius, bg_paint);
 
-  // Paint a white ring as the foreground. The ceil/dsf math assures that the
-  // ring draws sharply and is centered at all scale factors.

[Evan Stade, 2017/02/01 00:38:13]

This logic looks pretty intentional. Are you sure you aren't breaking something?

I'm pretty sure what you actually want is a ScopedCanvas to undo-undo-dsf.

[xdai1, 2017/02/01 01:14:06]

Sorry for the previous bad fix. Modified as you suggested. Thanks!

+  // Paint a white ring as the foreground.
   const float kRingOuterRadiusDp = 7.f;
   const float kRingThicknessDp = 1.5f;
-  const float dsf = canvas->UndoDeviceScaleFactor();
-  circle_center.Scale(dsf);
-
   SkPaint fg_paint;
   fg_paint.setFlags(SkPaint::kAntiAlias_Flag);
   fg_paint.setStyle(SkPaint::kStroke_Style);
   fg_paint.setColor(kShelfIconColor);
-  const float thickness = std::ceil(kRingThicknessDp * dsf);
-  const float radius = std::ceil(kRingOuterRadiusDp * dsf) - thickness / 2;
-  fg_paint.setStrokeWidth(thickness);
+  fg_paint.setStrokeWidth(kRingThicknessDp);
+  const float radius = kRingOuterRadiusDp - kRingThicknessDp / 2;
   // Make sure the center of the circle lands on pixel centers.
   canvas->DrawCircle(circle_center, radius, fg_paint);
 }