Adds remainder of support for multiple roots to WS

components/mus/public/cpp/window_manager_delegate.h

 // 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.
 
 #ifndef COMPONENTS_MUS_PUBLIC_CPP_WINDOW_MANAGER_DELEGATE_H_
 #define COMPONENTS_MUS_PUBLIC_CPP_WINDOW_MANAGER_DELEGATE_H_
 
 #include <stdint.h>
 
+#include <map>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 
 namespace gfx {
 class Rect;
 }
 
 namespace mus {
 
@@ skipping 11 matching lines @@
   // bounds the window should be in |bounds|.
   virtual bool OnWmSetBounds(Window* window, gfx::Rect* bounds) = 0;
 
   // A client requested the shared property named |name| to change to
   // |new_data|. Return true to allow the change to |new_data|, false
   // otherwise.
   virtual bool OnWmSetProperty(Window* window,
                                const std::string& name,
                                scoped_ptr<std::vector<uint8_t>>* new_data) = 0;
 
+  // A client has requested a new top level window. The delegate should create
+  // and parent the window appropriately and return it. |properties| is the
+  // supplied properties from the client requesting the new window. The
+  // delegate may modify |properties| before calling NewWindow(), but the
+  // delegate does *not* own |properties|, they are valid only for the life
+  // of OnWmCreateTopLevelWindow().
+  virtual Window* OnWmCreateTopLevelWindow(
+      std::map<std::string, std::vector<uint8_t>>* properties) = 0;
+
  protected:
   virtual ~WindowManagerDelegate() {}
 };
 
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_PUBLIC_CPP_WINDOW_MANAGER_DELEGATE_H_