Moves a couple of the maximize mode classes to ash/common

ash/wm/workspace/workspace_layout_manager_unittest.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/common/wm/workspace/workspace_layout_manager.h"
 
 #include <string>
 #include <utility>
 
 #include "ash/aura/wm_window_aura.h"
@@ skipping 874 matching lines @@
 
   aura::Window* CreateTestWindow(const gfx::Rect& bounds) {
     aura::Window* window = CreateTestWindowInShellWithBounds(bounds);
     return window;
   }
 
   // Turn the top window back drop on / off.
   void ShowTopWindowBackdrop(bool show) {
     std::unique_ptr<ash::WorkspaceLayoutManagerBackdropDelegate> backdrop;
     if (show) {
-      backdrop.reset(new ash::WorkspaceBackdropDelegate(default_container_));
+      backdrop.reset(new ash::WorkspaceBackdropDelegate(
+          WmWindowAura::Get(default_container_)));
     }
     GetWorkspaceLayoutManager(default_container_)
         ->SetMaximizeBackdropDelegate(std::move(backdrop));
     // Closing and / or opening can be a delayed operation.
     base::RunLoop().RunUntilIdle();
   }
 
   // Return the default container.
   aura::Window* default_container() { return default_container_; }
 
@@ skipping 287 matching lines @@
   EXPECT_EQ(gfx::Rect(50,
                       keyboard_bounds.y() - keyboard_bounds.height()/2,
                       occluded_window_bounds.width(),
                       occluded_window_bounds.height()).ToString(),
             window->bounds().ToString());
   HideKeyboard();
   EXPECT_EQ(occluded_window_bounds.ToString(), window->bounds().ToString());
 }
 
 }  // namespace ash