Set layout manager for product specification button

This fixes the size issue of the button https://screenshot.googleplex.com/4eLtCPBgLsTK428.

Bug: b/325661685
Change-Id: Ie8a17c89739e68e7f6def6d61c25f850df91d83e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5536154
Reviewed-by: Emily Shack <emshack@chromium.org>
Commit-Queue: Yue Zhang <yuezhanggg@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1300337}
diff --git a/chrome/browser/ui/views/commerce/product_specifications_button.cc b/chrome/browser/ui/views/commerce/product_specifications_button.cc
index c3cbde0b..2be9994f 100644
--- a/chrome/browser/ui/views/commerce/product_specifications_button.cc
+++ b/chrome/browser/ui/views/commerce/product_specifications_button.cc
@@ -18,6 +18,7 @@
 #include "ui/views/animation/ink_drop.h"
 #include "ui/views/controls/highlight_path_generator.h"
 #include "ui/views/layout/box_layout.h"
+#include "ui/views/layout/flex_layout.h"
 #include "ui/views/mouse_watcher_view_host.h"
 #include "ui/views/view_class_properties.h"
 
@@ -105,6 +106,8 @@
 
   layout_manager->SetFlexForView(close_button_, 1);
 
+  SetLayoutManager(std::make_unique<views::FlexLayout>());
+
   UpdateColors();
 }