Introduce AndroidFocusRules and NativeWidgetAndroid

ui/wm/android/android_focus_rules.cc

Index: ui/wm/android/android_focus_rules.cc
diff --git a/ui/wm/android/android_focus_rules.cc b/ui/wm/android/android_focus_rules.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8ef1790b6736896c9647df0cc841ad19ff587183
--- /dev/null
+++ b/ui/wm/android/android_focus_rules.cc
@@ -0,0 +1,19 @@
+// 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 "ui/wm/android/android_focus_rules.h"
+
+#include "ui/aura/window.h"
+
+namespace wm {
+
+AndroidFocusRules::AndroidFocusRules() {}
+
+AndroidFocusRules::~AndroidFocusRules() {}
+
+bool AndroidFocusRules::SupportsChildActivation(aura::Window* window) const {
+  return window->IsRootWindow();
+}
+
+}  // namespace wm