views: Add option in BoxLayout to spread blank space among the child views.

ui/views/layout/box_layout.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_LAYOUT_BOX_LAYOUT_H_
 #define UI_VIEWS_LAYOUT_BOX_LAYOUT_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 22 matching lines @@
   // Use |inside_border_horizontal_spacing| and
   // |inside_border_vertical_spacing| to add additional space between the child
   // view area and the host view border. |between_child_spacing| controls the
   // space in between child views.
   BoxLayout(Orientation orientation,
             int inside_border_horizontal_spacing,
             int inside_border_vertical_spacing,
             int between_child_spacing);
   virtual ~BoxLayout();
 
+  void set_spread_blank_space(bool spread) {
+    spread_blank_space_ = spread;
+  }
+
   // Overridden from views::LayoutManager:
   virtual void Layout(View* host) OVERRIDE;
   virtual gfx::Size GetPreferredSize(View* host) OVERRIDE;
 
  private:
   const Orientation orientation_;
 
   // Spacing between child views and host view border.
   const int inside_border_horizontal_spacing_;
   const int inside_border_vertical_spacing_;
 
   // Spacing to put in between child views.
   const int between_child_spacing_;
 
+  // Whether the available extra space should be distributed among the child
+  // views.
+  bool spread_blank_space_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(BoxLayout);
 };
 
 } // namespace views
 
 #endif  // UI_VIEWS_LAYOUT_BOX_LAYOUT_H_