[MD] Fix detached bookmark bar top separator in hdpi

chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc

Index: chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc
diff --git a/chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc b/chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc
index a9afc5d251e9cd09fefbc368f800c837d71b4358..5bd84c7e3843e5898d62524938e255af182dfdea 100644
--- a/chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc
+++ b/chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc
@@ -626,6 +626,7 @@ BookmarkBarView::BookmarkBarView(Browser* browser, BrowserView* browser_view)
     // Don't let the bookmarks show on top of the location bar while animating.
     SetPaintToLayer(true);
     layer()->SetMasksToBounds(true);
+    layer()->SetFillsBoundsOpaquely(false);
   }
 
   size_animation_.Reset(1);