content: Remove views dependency.

content/browser/compositor/mus_browser_compositor_output_surface.cc

Index: content/browser/compositor/mus_browser_compositor_output_surface.cc
diff --git a/content/browser/compositor/mus_browser_compositor_output_surface.cc b/content/browser/compositor/mus_browser_compositor_output_surface.cc
index 6e7a758773b44a368626f033c1eaea7357c88793..54fe4877a3979ffb82b01b86f573473da42ac1e3 100644
--- a/content/browser/compositor/mus_browser_compositor_output_surface.cc
+++ b/content/browser/compositor/mus_browser_compositor_output_surface.cc
@@ -15,8 +15,7 @@
 #include "gpu/ipc/client/command_buffer_proxy_impl.h"
 #include "services/ui/public/cpp/window.h"
 #include "services/ui/public/cpp/window_surface.h"
-#include "ui/views/mus/native_widget_mus.h"
-#include "ui/views/mus/window_tree_host_mus.h"
+#include "ui/base/view_prop.h"
 
 namespace content {
 
@@ -32,10 +31,8 @@ MusBrowserCompositorOutputSurface::MusBrowserCompositorOutputSurface(
                                         begin_frame_source,
                                         std::move(overlay_candidate_validator)),
       ui_window_(nullptr) {
-  views::WindowTreeHostMus* window_tree_host =
-      static_cast<views::WindowTreeHostMus*>(
-          aura::WindowTreeHost::GetForAcceleratedWidget(surface_handle));
-  ui_window_ = window_tree_host->native_widget()->window();
+  ui_window_ = reinterpret_cast<ui::Window*>(
+      ui::ViewProp::GetValue(surface_handle, ui::kWindowForAcceleratedWidget));
   ui_window_surface_ =
       ui_window_->RequestSurface(ui::mojom::SurfaceType::DEFAULT);
 }