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

ui/message_center/views/padded_button.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/padded_button.h"
 
 #include "grit/ui_resources.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas.h"
 #include "ui/message_center/message_center_style.h"
@@ skipping 32 matching lines @@
            ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
                resource_id));
 }
 
 void PaddedButton::SetPressedImage(int resource_id) {
   SetImage(views::CustomButton::STATE_PRESSED,
            ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
                resource_id));
 }
 
-gfx::Size PaddedButton::GetPreferredSize() {
+gfx::Size PaddedButton::GetPreferredSize() const {
   return gfx::Size(message_center::kControlButtonSize,
                    message_center::kControlButtonSize);
 }
 
 void PaddedButton::OnPaint(gfx::Canvas* canvas) {
   // This is the same implementation as ImageButton::OnPaint except
   // that it calls ComputePaddedImagePaintPosition() instead of
   // ComputeImagePaintPosition(), in effect overriding that private method.
   View::OnPaint(canvas);
   gfx::ImageSkia image = GetImageToPaint();
@@ skipping 24 matching lines @@
 
   if (padding_.top() == 0 && padding_.bottom() == 0)
     offset.set_y((bounds.height() - image.height()) / 2);  // Middle align.
   else if (padding_.bottom() > 0)
     offset.set_y(bounds.height() - image.height());  // Bottom align.
 
   return bounds.origin() + offset;
 }
 
 }  // namespace message_center