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

ui/app_list/views/top_icon_animation_view.cc

 // Copyright 2014 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/app_list/views/top_icon_animation_view.h"
 
 #include "ui/app_list/app_list_constants.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/gfx/image/image_skia_operations.h"
 #include "ui/views/controls/image_view.h"
@@ skipping 49 matching lines @@
   // Animate the icon to its target location and scale when opening or
   // closing a folder.
   ui::ScopedLayerAnimationSettings settings(layer()->GetAnimator());
   settings.AddObserver(this);
   settings.SetTweenType(gfx::Tween::FAST_OUT_SLOW_IN);
   settings.SetTransitionDuration(
       base::TimeDelta::FromMilliseconds(kFolderTransitionInDurationMs));
   layer()->SetTransform(open_folder_ ? gfx::Transform() : transform);
 }
 
-gfx::Size TopIconAnimationView::GetPreferredSize() {
+gfx::Size TopIconAnimationView::GetPreferredSize() const {
   return icon_size_;
 }
 
 void TopIconAnimationView::Layout() {
   icon_->SetBoundsRect(GetContentsBounds());
 }
 
 void TopIconAnimationView::OnImplicitAnimationsCompleted() {
   SetVisible(false);
   FOR_EACH_OBSERVER(TopIconAnimationObserver,
                     observers_,
                     OnTopIconAnimationsComplete());
   delete this;
 }
 
 bool TopIconAnimationView::RequiresNotificationWhenAnimatorDestroyed() const {
   return true;
 }
 
 }  // namespace app_list