Reland: Implement Aura side of unified touch text selection for contents

ui/touch_selection/touch_selection_menu_runner.cc

Index: ui/touch_selection/touch_selection_menu_runner.cc
diff --git a/ui/touch_selection/touch_selection_menu_runner.cc b/ui/touch_selection/touch_selection_menu_runner.cc
new file mode 100644
index 0000000000000000000000000000000000000000..358a086507ecc7dbc0f5374a1d7986ef96c3baed
--- /dev/null
+++ b/ui/touch_selection/touch_selection_menu_runner.cc
@@ -0,0 +1,28 @@
+// Copyright 2014 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/touch_selection/touch_selection_menu_runner.h"
+
+namespace ui {
+namespace {
+
+TouchSelectionMenuRunner* g_touch_selection_menu_runner = nullptr;
+
+}  // namespace
+
+TouchSelectionMenuRunner::~TouchSelectionMenuRunner() {
+}
+
+TouchSelectionMenuRunner* TouchSelectionMenuRunner::GetInstance() {
+  return g_touch_selection_menu_runner;
+}
+
+TouchSelectionMenuRunner::TouchSelectionMenuRunner() {
+}
+
+void TouchSelectionMenuRunner::SetInstance(TouchSelectionMenuRunner* instance) {
+  g_touch_selection_menu_runner = instance;
+}
+
+}  // namespace ui