views: Make view::Views::GetPreferredSize() const.

ui/views/examples/single_split_view_example.cc

Index: ui/views/examples/single_split_view_example.cc
diff --git a/ui/views/examples/single_split_view_example.cc b/ui/views/examples/single_split_view_example.cc
index 1258b058f0cccfc8a5e6e344363b9152bdaafe04..7e390b510646e791fd0785a4192788a7fc59b739 100644
--- a/ui/views/examples/single_split_view_example.cc
+++ b/ui/views/examples/single_split_view_example.cc
@@ -22,8 +22,8 @@ class SplittedView : public View {
 
  private:
   // View:
-  virtual gfx::Size GetPreferredSize() OVERRIDE;
-  virtual gfx::Size GetMinimumSize() OVERRIDE;
+  virtual gfx::Size GetPreferredSize() const OVERRIDE;
+  virtual gfx::Size GetMinimumSize() const OVERRIDE;
   virtual void Layout() OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(SplittedView);
@@ -40,11 +40,11 @@ void SplittedView::SetColor(SkColor from, SkColor to) {
   set_background(Background::CreateVerticalGradientBackground(from, to));
 }
 
-gfx::Size SplittedView::GetPreferredSize() {
+gfx::Size SplittedView::GetPreferredSize() const {
   return gfx::Size(width(), height());
 }
 
-gfx::Size SplittedView::GetMinimumSize() {
+gfx::Size SplittedView::GetMinimumSize() const {
   return gfx::Size(10, 10);
 }