Makes NewWindow() take set of properties for window

components/mus/public/interfaces/window_manager.mojom

 // Copyright 2015 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.
 
 module mus.mojom;
 
 import "components/mus/public/interfaces/window_manager_constants.mojom";
 import "components/mus/public/interfaces/window_tree.mojom";
 import "ui/mojo/geometry/geometry.mojom";
 
 struct WindowManagerConfig {
   array<Display> displays;
   mojo.Insets normal_client_area_insets;
   mojo.Insets maximized_client_area_insets;
 };
 
 // Represents a core interface that should be implemented by any window manager
 // built on top of Mus.
-// For security reasons, methods that take window_ids can only pass window ids
-// created by calls to OpenWindow() from the *same connection* to the window
-// manager. The callback indicates success or failure.
 interface WindowManager {
   // The window's preferred size as defined by its content. Type: gfx::Size.
   const string kPreferredSize_Property = "prop:preferred-size";
   // The window's resize behavior. Type: ResizeBehavior.
   const string kResizeBehavior_Property = "prop:resize-behavior";
   // Bounds the window is restored to. Type: gfx::Rect.
   const string kRestoreBounds_Property = "prop:restore-bounds";
+  // Shadow style for the window. Type mojom::ShadowStyle.
+  const string kShadowStyle_Property = "prop:shadow-style";
   // The window's show state. Type: ShowState.
   const string kShowState_Property = "prop:show-state";
   // The window bounds as set by user input. Type: gfx::Rect.
   const string kUserSetBounds_Property = "prop:user-set-bounds";
 
   OpenWindow(WindowTreeClient client, map<string, array<uint8>> properties);
 
   GetConfig() => (WindowManagerConfig config);
 };