views: fold layout_utils::CreatePanelLayout into GridLayout::CreatePanel

ui/views/layout/grid_layout.cc

Index: ui/views/layout/grid_layout.cc
diff --git a/ui/views/layout/grid_layout.cc b/ui/views/layout/grid_layout.cc
index 135fe19022c7677ba77bcae7900f4df595275cd1..6de7a05a170c7f653be2c27487f0e42956c9f590 100644
--- a/ui/views/layout/grid_layout.cc
+++ b/ui/views/layout/grid_layout.cc
@@ -11,6 +11,7 @@
 #include "base/memory/ptr_util.h"
 #include "ui/views/layout/layout_constants.h"
 #include "ui/views/view.h"
+#include "ui/views/views_delegate.h"
 #include "ui/views/window/dialog_delegate.h"
 
 namespace views {
@@ -651,8 +652,9 @@ GridLayout::~GridLayout() {
 // static
 GridLayout* GridLayout::CreatePanel(View* host) {
   GridLayout* layout = new GridLayout(host);
-  layout->SetInsets(kPanelVertMargin, kButtonHEdgeMarginNew,
-                    kPanelVertMargin, kButtonHEdgeMarginNew);
+  layout->SetInsets(
+      ViewsDelegate::GetInstance()->GetInsetsMetric(InsetsMetric::PANEL));
+  host->SetLayoutManager(layout);
   return layout;
 }