[MD] Fix bookmark bar button overflow during bar animation.

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 63a34c6ef1fce783b482cf61e5c3771f43be5e06..1b63bccd6a92c17224007dfcc7bc46904b36157e 100644
--- a/chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc
+++ b/chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc
@@ -616,6 +616,13 @@ BookmarkBarView::BookmarkBarView(Browser* browser, BrowserView* browser_view)
   set_id(VIEW_ID_BOOKMARK_BAR);
   Init();
 
+  if (ui::MaterialDesignController::IsModeMaterial()) {
+    // Don't let the bookmarks show on top of the location bar while animating.
+    SetPaintToLayer(true);
+    layer()->SetFillsBoundsOpaquely(false);
+    layer()->SetMasksToBounds(true);
+  }
+
   size_animation_.Reset(1);
 }