mus: Allow the WM to specify the windows that can have active children.

components/mus/ws/window_manager_client_apptest.cc

 // Copyright 2014 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 "base/bind.h"
 #include "base/logging.h"
 #include "base/run_loop.h"
 #include "components/mus/common/util.h"
 #include "components/mus/public/cpp/tests/window_server_test_base.h"
 #include "components/mus/public/cpp/window_observer.h"
@@ skipping 626 matching lines @@
     FocusChangeObserver observer(window11);
     window11->SetFocus();
     ASSERT_TRUE(DoRunLoopWithTimeout());
     ASSERT_NE(nullptr, observer.last_gained_focus());
     ASSERT_NE(nullptr, observer.last_lost_focus());
     EXPECT_EQ(window11->id(), observer.last_gained_focus()->id());
     EXPECT_EQ(embedded->GetRoot()->id(), observer.last_lost_focus()->id());
   }
   {
     // Add an observer on the Window that loses focus, and make sure the
-    // observer
-    // sees the right values.
+    // observer sees the right values.
     FocusChangeObserver observer(window11);
     embedded->GetRoot()->SetFocus();
     ASSERT_TRUE(DoRunLoopWithTimeout());
     ASSERT_NE(nullptr, observer.last_gained_focus());
     ASSERT_NE(nullptr, observer.last_lost_focus());
     EXPECT_EQ(window11->id(), observer.last_lost_focus()->id());
     EXPECT_EQ(embedded->GetRoot()->id(), observer.last_gained_focus()->id());
   }
 }
 
@@ skipping 230 matching lines @@
   WaitForBoundsToChange(embedded_connection->GetRoot());
   EXPECT_TRUE(gfx::Rect(21, 22, 23, 24) ==
               embedded_connection->GetRoot()->bounds());
   EXPECT_TRUE(gfx::Insets(1, 2, 3, 4) ==
               embedded_connection->GetRoot()->client_area());
 }
 
 }  // namespace ws
 
 }  // namespace mus