Routes calls to WM through WS

components/mus/public/interfaces/window_tree.mojom

Index: components/mus/public/interfaces/window_tree.mojom
diff --git a/components/mus/public/interfaces/window_tree.mojom b/components/mus/public/interfaces/window_tree.mojom
index d1218ad2b00696f3d7ea93f853a70cee9d0767a4..124ca9208df8976cb7b6aacd380132df0eaacb20 100644
--- a/components/mus/public/interfaces/window_tree.mojom
+++ b/components/mus/public/interfaces/window_tree.mojom
@@ -5,8 +5,9 @@
 module mus.mojom;
 
 import "components/mus/public/interfaces/compositor_frame.mojom";
-import "components/mus/public/interfaces/surface_id.mojom";
 import "components/mus/public/interfaces/mus_constants.mojom";
+import "components/mus/public/interfaces/surface_id.mojom";
+import "components/mus/public/interfaces/window_manager_constants.mojom";
 import "mojo/application/public/interfaces/service_provider.mojom";
 import "network/public/interfaces/url_loader.mojom";
 import "ui/mojo/events/input_events.mojom";
@@ -172,6 +173,19 @@ interface WindowTree {
   // If state is non-null, the specified window's text input state is updated.
   // Otherwise the existing state is used.
   SetImeVisibility(uint32 window_id, bool visible, mojo.TextInputState? state);
+
+  // --------------------------------------------------------------------------
+  // This section is for functions that call through directly to the
+  // WindowManager. It is expected this will move into an associated interface.
+  // See window_manager.mojom for details of these functions.
+  //   OpenWindow(WindowTreeClient client);
+  SetPreferredSize(uint32 window_id, mojo.Size size) =>
+      (WindowManagerErrorCode result);
+  SetBounds(uint32 window_id, mojo.Rect bounds) =>
+      (WindowManagerErrorCode result);
+  SetShowState(uint32 window_id, ShowState show_state) =>
+      (WindowManagerErrorCode result);
+  GetDisplays() => (array<Display> displays);
 };
 
 // Changes to windows are not sent to the connection that originated the