Tab dragging as implemented as a mus API.

services/ui/ws/default_access_policy.cc

 // 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 "services/ui/ws/default_access_policy.h"
 
 #include "services/ui/ws/access_policy_delegate.h"
 #include "services/ui/ws/server_window.h"
 
 namespace ui {
@@ skipping 137 matching lines @@
   return WasCreatedByThisClient(window) ||
          delegate_->HasRootForAccessPolicy(window);
 }
 
 bool DefaultAccessPolicy::CanSetCursorProperties(
     const ServerWindow* window) const {
   return WasCreatedByThisClient(window) ||
          delegate_->HasRootForAccessPolicy(window);
 }
 
+bool DefaultAccessPolicy::CanInitiateMoveLoop(
+    const ServerWindow* window) const {
+  return delegate_->HasRootForAccessPolicy(window);
+}
+
 bool DefaultAccessPolicy::ShouldNotifyOnHierarchyChange(
     const ServerWindow* window,
     const ServerWindow** new_parent,
     const ServerWindow** old_parent) const {
   if (!WasCreatedByThisClient(window))
     return false;
 
   if (*new_parent && !WasCreatedByThisClient(*new_parent) &&
       !delegate_->HasRootForAccessPolicy((*new_parent))) {
     *new_parent = nullptr;
@@ skipping 26 matching lines @@
 bool DefaultAccessPolicy::IsValidIdForNewWindow(
     const ClientWindowId& id) const {
   // Clients using DefaultAccessPolicy only see windows they have created (for
   // the embed point they choose the id), so it's ok for clients to use whatever
   // id they want.
   return true;
 }
 
 }  // namespace ws
 }  // namespace ui