ash: Refactor some code that snaps windows.

ash/wm/window_util.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/window_util.h"
 
 #include <vector>
 
 #include "ash/ash_constants.h"
 #include "ash/shell.h"
@@ skipping 68 matching lines @@
 bool CanMaximizeWindow(const aura::Window* window) {
   return window->GetProperty(aura::client::kCanMaximizeKey);
 }
 
 bool CanResizeWindow(const aura::Window* window) {
   return window->GetProperty(aura::client::kCanResizeKey);
 }
 
 bool CanSnapWindow(aura::Window* window) {
   // If a window has a maximum size defined, snapping may make it too big.
-  return window->delegate()->GetMaximumSize().IsEmpty();
+  return window->delegate() ? window->delegate()->GetMaximumSize().IsEmpty() :
+                              true;
 }
 
 bool IsWindowNormal(const aura::Window* window) {
   return IsWindowStateNormal(window->GetProperty(aura::client::kShowStateKey));
 }
 
 bool IsWindowStateNormal(ui::WindowShowState state) {
   return state == ui::SHOW_STATE_NORMAL || state == ui::SHOW_STATE_DEFAULT;
 }
 
@@ skipping 110 matching lines @@
       x_offset = work_area.right() - bounds->x() - kMinimumOnScreenArea;
     } else if (bounds->right() < work_area.x()) {
       x_offset = work_area.x() - bounds->right() + kMinimumOnScreenArea;
     }
     bounds->Offset(x_offset, y_offset);
   }
 }
 
 }  // namespace wm
 }  // namespace ash