Native themes: Add menu separator part

ui/native_theme/native_theme_win.cc

Index: ui/native_theme/native_theme_win.cc
diff --git a/ui/native_theme/native_theme_win.cc b/ui/native_theme/native_theme_win.cc
index 24eaae35e6953f266d2048093adef6e60e163320..1ebbb0e7197ddd286bcba41d8eb159183c94b06e 100644
--- a/ui/native_theme/native_theme_win.cc
+++ b/ui/native_theme/native_theme_win.cc
@@ -264,7 +264,7 @@ void NativeThemeWin::Paint(SkCanvas* canvas,
       PaintMenuGutter(canvas, rect);
       return;
     case kMenuPopupSeparator:
-      PaintMenuSeparator(canvas, rect);
+      PaintMenuSeparator(canvas, rect, extra.menu_separator);
       return;
     case kMenuPopupBackground:
       PaintMenuBackground(canvas, rect);
@@ -374,12 +374,15 @@ void NativeThemeWin::UpdateSystemColors() {
     system_colors_[kSystemColor] = color_utils::GetSysSkColor(kSystemColor);
 }
 
-void NativeThemeWin::PaintMenuSeparator(SkCanvas* canvas,
-                                        const gfx::Rect& rect) const {
+void NativeThemeWin::PaintMenuSeparator(
+    SkCanvas* canvas,
+    const gfx::Rect& rect,
+    const MenuSeparatorExtraParams& extra) const {
   SkPaint paint;
   paint.setColor(GetSystemColor(NativeTheme::kColorId_MenuSeparatorColor));
-  int position_y = rect.y() + rect.height() / 2;
-  canvas->drawLine(rect.x(), position_y, rect.right(), position_y, paint);
+  int position_y = extra.paint_rect->y() + extra.paint_rect->height() / 2;
+  canvas->drawLine(extra.paint_rect->x(), position_y, extra.paint_rect->right(),
+                   position_y, paint);
 }
 
 void NativeThemeWin::PaintMenuGutter(SkCanvas* canvas,
@@ -429,7 +432,7 @@ void NativeThemeWin::PaintDirect(SkCanvas* destination_canvas,
       PaintMenuGutter(hdc, rect);
       return;
     case kMenuPopupSeparator:
-      PaintMenuSeparator(hdc, rect);
+      PaintMenuSeparator(hdc, rect, extra.menu_separator);
       return;
     case kMenuItemBackground:
       PaintMenuItemBackground(hdc, state, rect, extra.menu_item);
@@ -868,8 +871,9 @@ HRESULT NativeThemeWin::PaintButton(HDC hdc,
 
 HRESULT NativeThemeWin::PaintMenuSeparator(
     HDC hdc,
-    const gfx::Rect& rect) const {
-  RECT rect_win = rect.ToRECT();
+    const gfx::Rect& rect,
+    const MenuSeparatorExtraParams& extra) const {
+  RECT rect_win = extra.paint_rect->ToRECT();
 
   HANDLE handle = GetThemeHandle(MENU);
   if (handle && draw_theme_) {