Converts ShellObserver from aura::Window to ash::WmWindow

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 56 matching lines @@
   TestShellObserver() : call_count_(0),
                         is_fullscreen_(false) {
     Shell::GetInstance()->AddShellObserver(this);
   }
 
   ~TestShellObserver() override {
     Shell::GetInstance()->RemoveShellObserver(this);
   }
 
   void OnFullscreenStateChanged(bool is_fullscreen,
-                                aura::Window* root_window) override {
+                                WmWindow* root_window) override {
     call_count_++;
     is_fullscreen_ = is_fullscreen;
   }
 
   int call_count() const {
     return call_count_;
   }
 
   bool is_fullscreen() const {
     return is_fullscreen_;
@@ skipping 1064 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