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

ui/views/controls/single_split_view.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/single_split_view.h"
 
 #include "skia/ext/skia_utils_win.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/base/cursor/cursor.h"
 #include "ui/gfx/canvas.h"
@@ skipping 47 matching lines @@
 
 const char* SingleSplitView::GetClassName() const {
   return kViewClassName;
 }
 
 void SingleSplitView::GetAccessibleState(ui::AXViewState* state) {
   state->role = ui::AX_ROLE_GROUP;
   state->name = accessible_name_;
 }
 
-gfx::Size SingleSplitView::GetPreferredSize() {
+gfx::Size SingleSplitView::GetPreferredSize() const {
   int width = 0;
   int height = 0;
   for (int i = 0; i < 2 && i < child_count(); ++i) {
-    View* view = child_at(i);
+    const View* view = child_at(i);
     gfx::Size pref = view->GetPreferredSize();
     if (is_horizontal_) {
       width += pref.width();
       height = std::max(height, pref.height());
     } else {
       width = std::max(width, pref.width());
       height += pref.height();
     }
   }
   if (is_horizontal_)
@@ skipping 161 matching lines @@
                                             const gfx::Rect& bounds) const {
   int primary_axis_size = GetPrimaryAxisSize(bounds.width(), bounds.height());
   if (divider_offset < 0)
     // primary_axis_size may < GetDividerSize during initial layout.
     return std::max(0, (primary_axis_size - GetDividerSize()) / 2);
   return std::min(divider_offset,
                   std::max(primary_axis_size - GetDividerSize(), 0));
 }
 
 }  // namespace views