chromeos: makes it possible for windows to outlive WindowTreeClient

ui/aura/window_port_for_shutdown.cc

Index: ui/aura/window_port_for_shutdown.cc
diff --git a/ui/aura/window_port_for_shutdown.cc b/ui/aura/window_port_for_shutdown.cc
new file mode 100644
index 0000000000000000000000000000000000000000..78ca06cb7e8226674f9b99541487f729951c3993
--- /dev/null
+++ b/ui/aura/window_port_for_shutdown.cc
@@ -0,0 +1,63 @@
+// Copyright 2017 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/aura/window_port_for_shutdown.h"
+
+#include "base/memory/ptr_util.h"
+#include "cc/output/compositor_frame_sink.h"
+#include "ui/aura/window.h"
+
+namespace aura {
+
+WindowPortForShutdown::WindowPortForShutdown() {}
+
+WindowPortForShutdown::~WindowPortForShutdown() {}
+
+// static
+void WindowPortForShutdown::Install(aura::Window* window) {
+  window->port_owner_.reset(new WindowPortForShutdown);
+  window->port_ = window->port_owner_.get();
+}
+
+void WindowPortForShutdown::OnPreInit(Window* window) {}
+
+void WindowPortForShutdown::OnDeviceScaleFactorChanged(
+    float device_scale_factor) {}
+
+void WindowPortForShutdown::OnWillAddChild(Window* child) {}
+
+void WindowPortForShutdown::OnWillRemoveChild(Window* child) {}
+
+void WindowPortForShutdown::OnWillMoveChild(size_t current_index,
+                                            size_t dest_index) {}
+
+void WindowPortForShutdown::OnVisibilityChanged(bool visible) {}
+
+void WindowPortForShutdown::OnDidChangeBounds(const gfx::Rect& old_bounds,
+                                              const gfx::Rect& new_bounds) {}
+
+std::unique_ptr<ui::PropertyData> WindowPortForShutdown::OnWillChangeProperty(
+    const void* key) {
+  return nullptr;
+}
+
+void WindowPortForShutdown::OnPropertyChanged(
+    const void* key,
+    int64_t old_value,
+    std::unique_ptr<ui::PropertyData> data) {}
+
+std::unique_ptr<cc::CompositorFrameSink>
+WindowPortForShutdown::CreateCompositorFrameSink() {
+  return nullptr;
+}
+
+cc::SurfaceId WindowPortForShutdown::GetSurfaceId() const {
+  return cc::SurfaceId();
+}
+
+void WindowPortForShutdown::OnWindowAddedToRootWindow() {}
+
+void WindowPortForShutdown::OnWillRemoveWindowFromRootWindow() {}
+
+}  // namespace aura