chromeos: makes mus send keyevents to display root when nothing has focus

services/ui/ws/window_manager_display_root.cc

 // Copyright 2016 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 "services/ui/ws/window_manager_display_root.h"
 
 #include <string>
 #include <vector>
 
 #include "services/ui/public/interfaces/window_manager.mojom.h"
 #include "services/ui/ws/display.h"
 #include "services/ui/ws/display_manager.h"
 #include "services/ui/ws/server_window.h"
+#include "services/ui/ws/window_manager_state.h"
 #include "services/ui/ws/window_server.h"
+#include "services/ui/ws/window_tree.h"
 
 namespace ui {
 namespace ws {
 
 WindowManagerDisplayRoot::WindowManagerDisplayRoot(Display* display)
     : display_(display) {
   std::string name = "WindowManagerRoot";
   ServerWindow::Properties properties;
   properties[mojom::WindowManager::kName_Property] =
       std::vector<uint8_t>(name.begin(), name.end());
 
   root_.reset(window_server()->CreateServerWindow(
       window_server()->display_manager()->GetAndAdvanceNextRootId(),
       properties));
   root_->set_event_targeting_policy(
       mojom::EventTargetingPolicy::DESCENDANTS_ONLY);
   // Our root is always a child of the Display's root. Do this
   // before the WindowTree has been created so that the client doesn't get
   // notified of the add, bounds change and visibility change.
   root_->SetBounds(gfx::Rect(display->root_window()->bounds().size()),
                    allocator_.GenerateId());
   root_->SetVisible(true);
   display->root_window()->Add(root_.get());
 }
 
 WindowManagerDisplayRoot::~WindowManagerDisplayRoot() {}
 
+const ServerWindow* WindowManagerDisplayRoot::GetClientVisibileRoot() const {
+  if (window_manager_state_->window_tree()
+          ->automatically_create_display_roots()) {
+    return root_.get();
+  }
+
+  return root_->children().empty() ? nullptr : root_->children()[0];
+}
+
 WindowServer* WindowManagerDisplayRoot::window_server() {
   return display_->window_server();
 }
 
 }  // namespace ws
 }  // namespace ui