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

ui/views/controls/image_view.h

Index: ui/views/controls/image_view.h
diff --git a/ui/views/controls/image_view.h b/ui/views/controls/image_view.h
index d82cf98b79a58ff57d43cc1331139a3da0773bf2..329981ee1a96097f5f11fd4d72bb007a9813e985 100644
--- a/ui/views/controls/image_view.h
+++ b/ui/views/controls/image_view.h
@@ -55,7 +55,7 @@ class VIEWS_EXPORT ImageView : public View {
   // Return the preferred size for the receiving view. Returns false if the
   // preferred size is not defined, which means that the view uses the image
   // size.
-  bool GetImageSize(gfx::Size* image_size);
+  bool GetImageSize(gfx::Size* image_size) const;
 
   // Returns the actual bounds of the visible image inside the view.
   gfx::Rect GetImageBounds() const;
@@ -80,7 +80,7 @@ class VIEWS_EXPORT ImageView : public View {
   void SetFocusPainter(scoped_ptr<Painter> focus_painter);
 
   // Overriden from View:
-  virtual gfx::Size GetPreferredSize() OVERRIDE;
+  virtual gfx::Size GetPreferredSize() const OVERRIDE;
   virtual void OnFocus() OVERRIDE;
   virtual void OnBlur() OVERRIDE;
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;