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

ui/message_center/views/proportional_image_view.cc

 // Copyright 2013 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.
 
 #include "ui/message_center/views/proportional_image_view.h"
 
 #include "ui/gfx/canvas.h"
 #include "ui/message_center/message_center_style.h"
 
 namespace message_center {
 
 ProportionalImageView::ProportionalImageView(const gfx::ImageSkia& image,
                                              const gfx::Size& max_size)
     : image_(image), max_size_(max_size) {}
 
 ProportionalImageView::~ProportionalImageView() {}
 
-gfx::Size ProportionalImageView::GetPreferredSize() { return max_size_; }
+gfx::Size ProportionalImageView::GetPreferredSize() const { return max_size_; }
 
-int ProportionalImageView::GetHeightForWidth(int width) {
+int ProportionalImageView::GetHeightForWidth(int width) const {
   return max_size_.height();
 }
 
 void ProportionalImageView::OnPaint(gfx::Canvas* canvas) {
   views::View::OnPaint(canvas);
 
   gfx::Size draw_size = GetImageDrawingSize();
 
   if (draw_size.IsEmpty())
     return;
@@ skipping 20 matching lines @@
 }
 
 gfx::Size ProportionalImageView::GetImageDrawingSize() {
   if (!visible())
     return gfx::Size();
   return message_center::GetImageSizeForContainerSize(
       GetContentsBounds().size(), image_.size());
 }
 
 }  // namespace message_center