Fixes use after free caused by delete in RootWindowController

ash/wm/frame_painter.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 "ash/wm/frame_painter.h"
 
 #include <vector>
 
 #include "ash/ash_constants.h"
 #include "ash/root_window_controller.h"
@@ skipping 159 matching lines @@
       window->layer() &&
       window->layer()->type() != ui::LAYER_NOT_DRAWN &&
       window->GetProperty(aura::client::kModalKey) == ui::MODAL_TYPE_NONE &&
       !window->GetProperty(ash::kConstrainedWindowKey);
 }
 
 // Returns a list of windows in |root_window|| that potentially could have
 // a transparent solo-window header.
 std::vector<Window*> GetWindowsForSoloHeaderUpdate(RootWindow* root_window) {
   std::vector<Window*> windows;
-  // During shutdown there may not be a workspace controller. In that case
-  // we don't care about updating any windows.
   // Avoid memory allocations for typical window counts.
   windows.reserve(16);
   // Collect windows from the desktop.
   Window* desktop = ash::Shell::GetContainer(
       root_window, ash::internal::kShellWindowId_DefaultContainer);
   windows.insert(windows.end(),
                  desktop->children().begin(),
                  desktop->children().end());
   // Collect "always on top" windows.
   Window* top_container =
@@ skipping 643 matching lines @@
   // icon. Don't use |window_icon_| for this computation as it may be NULL.
   int title_y = GetCaptionButtonContainerCenterY() - title_font.GetHeight() / 2;
   return gfx::Rect(
       title_x,
       std::max(0, title_y),
       std::max(0, caption_button_container_->x() - kTitleLogoSpacing - title_x),
       title_font.GetHeight());
 }
 
 }  // namespace ash