views/mus: Add support for child widgets.

ui/views/mus/window_manager_connection.cc

 // 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.
 
 #include "ui/views/mus/window_manager_connection.h"
 
 #include <utility>
 
 #include "base/lazy_instance.h"
 #include "base/threading/thread_local.h"
@@ skipping 50 matching lines @@
 
 mus::Window* WindowManagerConnection::NewWindow(
     const std::map<std::string, std::vector<uint8_t>>& properties) {
   return window_tree_connection_->NewTopLevelWindow(&properties);
 }
 
 NativeWidget* WindowManagerConnection::CreateNativeWidgetMus(
     const std::map<std::string, std::vector<uint8_t>>& props,
     const Widget::InitParams& init_params,
     internal::NativeWidgetDelegate* delegate) {
+  if (init_params.type == Widget::InitParams::TYPE_CONTROL)
+    return nullptr;

[sky, 2016/05/31 17:00:57]

Add comment as to what ends up handling this.

[sadrul, 2016/05/31 17:25:14]

Done.

   std::map<std::string, std::vector<uint8_t>> properties = props;
   NativeWidgetMus::ConfigurePropertiesForNewWindow(init_params, &properties);
   properties[mus::mojom::WindowManager::kAppID_Property] =
       mojo::ConvertTo<std::vector<uint8_t>>(identity_.name());
   return new NativeWidgetMus(delegate, connector_, NewWindow(properties),
                              mus::mojom::SurfaceType::DEFAULT);
 }
 
 void WindowManagerConnection::AddPointerWatcher(PointerWatcher* watcher) {
   bool had_watcher = HasPointerWatcher();
@@ skipping 88 matching lines @@
 void WindowManagerConnection::OnWindowManagerFrameValuesChanged() {
   if (window_tree_connection_)
     NativeWidgetMus::NotifyFrameChanged(window_tree_connection_.get());
 }
 
 gfx::Point WindowManagerConnection::GetCursorScreenPoint() {
   return window_tree_connection_->GetCursorScreenPoint();
 }
 
 }  // namespace views