Harmony - Use FocusableBorder for comboboxes on Mac

ui/views/style/platform_style.cc

Index: ui/views/style/platform_style.cc
diff --git a/ui/views/style/platform_style.cc b/ui/views/style/platform_style.cc
index 132552067bc7d2a2622caa9cc9a0c2144c750859..b586060750c0b259e6d37f8f27caf8c9a4ed2ca6 100644
--- a/ui/views/style/platform_style.cc
+++ b/ui/views/style/platform_style.cc
@@ -53,17 +53,6 @@ gfx::ImageSkia PlatformStyle::CreateComboboxArrow(bool is_enabled,
 }
 
 // static
-std::unique_ptr<FocusableBorder> PlatformStyle::CreateComboboxBorder() {
-  return base::MakeUnique<FocusableBorder>();
-}
-
-// static
-std::unique_ptr<Background> PlatformStyle::CreateComboboxBackground(
-    int shoulder_width) {
-  return nullptr;
-}
-
-// static
 std::unique_ptr<ScrollBar> PlatformStyle::CreateScrollBar(bool is_horizontal) {
   return base::MakeUnique<NativeScrollBar>(is_horizontal);
 }