Renames aura::client::WindowTreeClient to WindowParentingClient

ui/views/widget/native_widget_aura.cc

Index: ui/views/widget/native_widget_aura.cc
diff --git a/ui/views/widget/native_widget_aura.cc b/ui/views/widget/native_widget_aura.cc
index 874417b0b86edf00ad41e63a20af3d75b6b44836..f9bdac6fbb95bc49885b5531f2a9f9f990ed208d 100644
--- a/ui/views/widget/native_widget_aura.cc
+++ b/ui/views/widget/native_widget_aura.cc
@@ -17,7 +17,7 @@
 #include "ui/aura/client/cursor_client.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/client/screen_position_client.h"
-#include "ui/aura/client/window_tree_client.h"
+#include "ui/aura/client/window_parenting_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
@@ -1171,8 +1171,8 @@ void NativeWidgetPrivate::ReparentNativeView(gfx::NativeView native_view,
   } else {
     // The following looks weird, but it's the equivalent of what aura has
     // always done. (The previous behaviour of aura::Window::SetParent() used
-    // NULL as a special value that meant ask the WindowTreeClient where things
-    // should go.)
+    // NULL as a special value that meant ask the WindowParentingClient where
+    // things should go.)
     //
     // This probably isn't strictly correct, but its an invariant that a Window
     // in use will be attached to a RootWindow, so we can't just call