views: Restore to old behaviour of Widget::ReparentNativeView().

ui/views/controls/native/native_view_host_aura_unittest.cc

 // Copyright (c) 2013 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 "ui/views/controls/native/native_view_host_aura.h"
 
 #include <memory>
 
 #include "base/macros.h"
 #include "ui/aura/client/aura_constants.h"
@@ skipping 239 matching lines @@
             clipping_window()->bounds().ToString());
 
   DestroyHost();
 }
 
 // Ensure native view is parented to the root window after detaching. This is
 // a regression test for http://crbug.com/389261.
 TEST_F(NativeViewHostAuraTest, ParentAfterDetach) {
   CreateHost();
   aura::Window* child_win = child()->GetNativeView();
+  aura::Window* root_window = child_win->GetRootWindow();
+  aura::WindowTreeHost* child_win_tree_host = child_win->GetHost();
 
   NativeViewHostWindowObserver test_observer;
   child_win->AddObserver(&test_observer);
 
   host()->Detach();
-  EXPECT_EQ(nullptr, child_win->GetRootWindow());
-  EXPECT_EQ(nullptr, child_win->GetHost());
+  EXPECT_EQ(root_window, child_win->GetRootWindow());
+  EXPECT_EQ(child_win_tree_host, child_win->GetHost());
 
   DestroyHost();
+  DestroyTopLevel();
+  if (!IsMus()) {
+    // The window is detached, so no longer associated with any Widget
+    // hierarchy. The root window still owns it, but the test harness checks
+    // for orphaned windows during TearDown().
+    EXPECT_EQ(0u, test_observer.events().size())
+        << (*test_observer.events().begin()).type;
+    delete child_win;
+  } else {
+    // In mus, the child window is still attached to the aura::WindowTreeHost
+    // for the Widget. So destroying the toplevel Widget takes down the child
+    // window with it.
+  }
 
-  // The window is detached, so no longer associated with any Widget hierarchy.
-  // The root window still owns it, but the test harness checks for orphaned
-  // windows during TearDown().
-  DestroyTopLevel();
-  EXPECT_EQ(0u, test_observer.events().size());
-  delete child_win;
   ASSERT_EQ(1u, test_observer.events().size());
   EXPECT_EQ(NativeViewHostWindowObserver::EVENT_DESTROYED,
             test_observer.events().back().type);
 }
 
 // Ensure the clipping window is hidden before setting the native view's bounds.
 // This is a regression test for http://crbug.com/388699.
 TEST_F(NativeViewHostAuraTest, RemoveClippingWindowOrder) {
   CreateHost();
   toplevel()->SetBounds(gfx::Rect(20, 20, 100, 100));
@@ skipping 75 matching lines @@
 
   host()->SetVisible(false);
   EXPECT_FALSE(clipping_window()->IsVisible());
   EXPECT_FALSE(child()->IsVisible());
 
   DestroyHost();
   DestroyTopLevel();
 }
 
 }  // namespace views