Introduce AndroidFocusRules and NativeWidgetAndroid

ui/views/widget/desktop_android/android_focus_rules.cc

Index: ui/views/widget/desktop_android/android_focus_rules.cc
diff --git a/ipc/ipc_message_attachment.cc b/ui/views/widget/desktop_android/android_focus_rules.cc
similarity index 34%
copy from ipc/ipc_message_attachment.cc
copy to ui/views/widget/desktop_android/android_focus_rules.cc
index 83440ae8e008847eebd411f8ffd08c69d9f529fe..88903a9a3b72973fb252ff750e123694bc431362 100644
--- a/ipc/ipc_message_attachment.cc
+++ b/ui/views/widget/desktop_android/android_focus_rules.cc
@@ -2,14 +2,18 @@
 // 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() {}
 
-MessageAttachment::~MessageAttachment() {
+bool AndroidFocusRules::SupportsChildActivation(aura::Window* window) const {
+  return window->IsRootWindow();
 }
 
-}  // namespace IPC
+}  // namespace views