Remove GridLayout::SetInsets in favor of an empty border on the host.

ui/views/layout/grid_layout.h

Index: ui/views/layout/grid_layout.h
diff --git a/ui/views/layout/grid_layout.h b/ui/views/layout/grid_layout.h
index 197d101705caa195f5fd7c98fc20ab973187dc93..66d9f65a99591e60064e349c30ed1a09a96eae3b 100644
--- a/ui/views/layout/grid_layout.h
+++ b/ui/views/layout/grid_layout.h
@@ -11,7 +11,6 @@
 #include <vector>
 
 #include "base/macros.h"
-#include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/views/layout/layout_manager.h"
 
@@ -104,13 +103,10 @@ class VIEWS_EXPORT GridLayout : public LayoutManager {
   explicit GridLayout(View* host);
   ~GridLayout() override;
 
-  // Creates a GridLayout with kPanel*Margin insets.
+  // Creates a GridLayout, assigns it as the LayoutManager of |host|, and gives
+  // it a INSETS_PANEL-sized padding border.
   static GridLayout* CreatePanel(View* host);
 
-  // Sets the insets. All views are placed relative to these offsets.
-  void SetInsets(int top, int left, int bottom, int right);
-  void SetInsets(const gfx::Insets& insets);
-
   // Creates a new column set with the specified id and returns it.
   // The id is later used when starting a new row.
   // GridLayout takes ownership of the ColumnSet and will delete it when
@@ -239,9 +235,6 @@ class VIEWS_EXPORT GridLayout : public LayoutManager {
   // Column set for the current row. This is null for padding rows.
   ColumnSet* current_row_col_set_;
 
-  // Insets.
-  gfx::Insets insets_;
-
   // Set to true when adding a View.
   bool adding_view_;