Update the layout mode first when exiting tablet mode

ash/common/wm_shell.cc

 // Copyright 2016 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_shell.h"
 
 #include <utility>
 
 #include "ash/common/accelerators/accelerator_controller.h"
 #include "ash/common/accelerators/ash_focus_manager_factory.h"
@@ skipping 164 matching lines @@
   DCHECK_GT(GetSessionStateDelegate()->NumberOfLoggedInUsers(), 0);
   shelf_delegate_.reset(delegate_->CreateShelfDelegate(shelf_model()));
   shelf_window_watcher_.reset(new ShelfWindowWatcher(shelf_model()));
 }
 
 void WmShell::OnMaximizeModeStarted() {
   for (auto& observer : shell_observers_)
     observer.OnMaximizeModeStarted();
 }
 
+void WmShell::OnMaximizeModeEnding() {
+  for (auto& observer : shell_observers_)
+    observer.OnMaximizeModeEnding();
+}
+
 void WmShell::OnMaximizeModeEnded() {
   for (auto& observer : shell_observers_)
     observer.OnMaximizeModeEnded();
 }
 
 void WmShell::UpdateAfterLoginStatusChange(LoginStatus status) {
   for (WmWindow* root_window : GetAllRootWindows()) {
     root_window->GetRootWindowController()->UpdateAfterLoginStatusChange(
         status);
   }
@@ skipping 261 matching lines @@
 
 void WmShell::OnAttemptToReactivateWindow(aura::Window* request_active,
                                           aura::Window* actual_active) {
   for (auto& observer : activation_observers_) {
     observer.OnAttemptToReactivateWindow(WmWindow::Get(request_active),
                                          WmWindow::Get(actual_active));
   }
 }
 
 }  // namespace ash