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

services/ui/ws/window_manager_display_root.h

 // 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.
 
 #ifndef SERVICES_UI_WS_WINDOW_MANAGER_DISPLAY_ROOT_H_
 #define SERVICES_UI_WS_WINDOW_MANAGER_DISPLAY_ROOT_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 10 matching lines @@
 class WindowServer;
 
 // Owns the root window of a window manager for one display. Each window manager
 // has one WindowManagerDisplayRoot for each Display. The root window is
 // parented to the root of a Display.
 class WindowManagerDisplayRoot {
  public:
   explicit WindowManagerDisplayRoot(Display* display);
   ~WindowManagerDisplayRoot();
 
+  // NOTE: this window is not necessarily visible to the window manager. When
+  // the display roots are automatically created this root is visible to the
+  // window manager. When the display roots are not automatically created this
+  // root has a single child that is created by the client. Use
+  // GetClientVisibileRoot() to get the root that is visible to the client.
   ServerWindow* root() { return root_.get(); }
   const ServerWindow* root() const { return root_.get(); }
 
+  // See root() for details of this. This returns null until the client creates
+  // the root.
+  ServerWindow* GetClientVisibileRoot() {
+    return const_cast<ServerWindow*>(
+        const_cast<const WindowManagerDisplayRoot*>(this)
+            ->GetClientVisibileRoot());
+  }
+  const ServerWindow* GetClientVisibileRoot() const;
+
   Display* display() { return display_; }
   const Display* display() const { return display_; }
 
   WindowManagerState* window_manager_state() { return window_manager_state_; }
   const WindowManagerState* window_manager_state() const {
     return window_manager_state_;
   }
 
  private:
   friend class Display;
   friend class WindowManagerState;
 
   WindowServer* window_server();
 
   Display* display_;
   // Root ServerWindow of this WindowManagerDisplayRoot. |root_| has a parent,
   // the root ServerWindow of the Display.
   std::unique_ptr<ServerWindow> root_;
   WindowManagerState* window_manager_state_ = nullptr;
   cc::LocalSurfaceIdAllocator allocator_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowManagerDisplayRoot);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_WINDOW_MANAGER_DISPLAY_ROOT_H_