Introduce AndroidFocusRules and NativeWidgetAndroid

ui/views/widget/desktop_android/android_focus_rules.cc

 // Copyright (c) 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 "ipc/ipc_message_attachment.h"
+#include "ui/views/widget/desktop_android/android_focus_rules.h"
 
-namespace IPC {
+#include "ui/aura/window.h"
 
-MessageAttachment::MessageAttachment() {
+namespace views {
+
+AndroidFocusRules::AndroidFocusRules() {}
+
+AndroidFocusRules::~AndroidFocusRules() {}
+
+bool AndroidFocusRules::SupportsChildActivation(aura::Window* window) const {
+  return window->IsRootWindow();
 }
 
-MessageAttachment::~MessageAttachment() {
-}
-
-}  // namespace IPC
+}  // namespace views