mash: Relay some Chrome aura window properties to Ash.

ui/views/mus/desktop_window_tree_host_mus.cc

Index: ui/views/mus/desktop_window_tree_host_mus.cc
diff --git a/ui/views/mus/desktop_window_tree_host_mus.cc b/ui/views/mus/desktop_window_tree_host_mus.cc
index 22730162d1e027dc5a80d2f7b5399d245a236918..a93effd3b0efee4603b06679a1ffe059ed43c185 100644
--- a/ui/views/mus/desktop_window_tree_host_mus.cc
+++ b/ui/views/mus/desktop_window_tree_host_mus.cc
@@ -20,6 +20,7 @@
 #include "ui/gfx/geometry/dip_util.h"
 #include "ui/views/corewm/tooltip_aura.h"
 #include "ui/views/mus/mus_client.h"
+#include "ui/views/mus/mus_property_mirror.h"
 #include "ui/views/mus/window_manager_frame_values.h"
 #include "ui/views/widget/desktop_aura/desktop_native_widget_aura.h"
 #include "ui/views/widget/native_widget_aura.h"
@@ -182,6 +183,7 @@ DesktopWindowTreeHostMus::DesktopWindowTreeHostMus(
   aura::Env::GetInstance()->AddObserver(this);
   MusClient::Get()->AddObserver(this);
   native_widget_delegate_->AsWidget()->AddObserver(this);
+  desktop_native_widget_aura_->content_window()->AddObserver(this);
   // DesktopNativeWidgetAura registers the association between |content_window_|
   // and Widget, but code may also want to go from the root (window()) to the
   // Widget. This call enables that.
@@ -196,6 +198,7 @@ DesktopWindowTreeHostMus::~DesktopWindowTreeHostMus() {
   // the cursor-client needs to be unset on the root-window before
   // |cursor_manager_| is destroyed.
   aura::client::SetCursorClient(window(), nullptr);
+  desktop_native_widget_aura_->content_window()->RemoveObserver(this);
   native_widget_delegate_->AsWidget()->RemoveObserver(this);
   MusClient::Get()->RemoveObserver(this);
   aura::Env::GetInstance()->RemoveObserver(this);
@@ -693,6 +696,22 @@ void DesktopWindowTreeHostMus::OnWidgetActivationChanged(Widget* widget,
   is_active_ = active;
 }
 
+void DesktopWindowTreeHostMus::OnWindowPropertyChanged(aura::Window* window,
+                                                       const void* key,
+                                                       intptr_t old) {
+  DCHECK_EQ(window, desktop_native_widget_aura_->content_window());
+  DCHECK(!window->GetRootWindow() || this->window() == window->GetRootWindow());
+  if (!this->window())
+    return;
+
+  // Allow mus clients to mirror widget window properties to their root windows.
+  MusPropertyMirror* property_mirror = MusClient::Get()->mus_property_mirror();
+  if (property_mirror) {
+    property_mirror->MirrorPropertyFromWidgetWindowToRootWindow(
+        window, this->window(), key);
+  }
+}
+
 void DesktopWindowTreeHostMus::ShowImpl() {
   native_widget_delegate_->OnNativeWidgetVisibilityChanging(true);
   // Using ui::SHOW_STATE_NORMAL matches that of DesktopWindowTreeHostX11.