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

ui/views/controls/separator.cc

 // Copyright (c) 2012 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/views/controls/separator.h"
 
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/gfx/canvas.h"
 
 namespace views {
@@ skipping 10 matching lines @@
 Separator::Separator(Orientation orientation) : orientation_(orientation) {
   SetFocusable(false);
 }
 
 Separator::~Separator() {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Separator, View overrides:
 
-gfx::Size Separator::GetPreferredSize() {
+gfx::Size Separator::GetPreferredSize() const {
   if (orientation_ == HORIZONTAL)
     return gfx::Size(width(), kSeparatorHeight);
   return gfx::Size(kSeparatorHeight, height());
 }
 
 void Separator::GetAccessibleState(ui::AXViewState* state) {
   state->role = ui::AX_ROLE_SPLITTER;
 }
 
 void Separator::Paint(gfx::Canvas* canvas, const views::CullSet& cull_set) {
   canvas->FillRect(bounds(), kDefaultColor);
 }
 
 const char* Separator::GetClassName() const {
   return kViewClassName;
 }
 
 }  // namespace views