Revert 114095 - Move the concept of Activation to the Shell.

ui/aura/client/activation_client.cc

Index: ui/aura/client/activation_client.cc
===================================================================
--- ui/aura/client/activation_client.cc	(revision 114098)
+++ ui/aura/client/activation_client.cc	(working copy)
@@ -1,23 +0,0 @@
-// Copyright (c) 2011 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/aura/client/activation_client.h"
-
-#include "ui/aura/client/aura_constants.h"
-#include "ui/aura/root_window.h"
-
-namespace aura {
-
-// static
-void ActivationClient::SetActivationClient(ActivationClient* client) {
-  RootWindow::GetInstance()->SetProperty(kRootWindowActivationClient, client);
-}
-
-// static
-ActivationClient* ActivationClient::GetActivationClient() {
-  return reinterpret_cast<ActivationClient*>(
-      RootWindow::GetInstance()->GetProperty(kRootWindowActivationClient));
-}
-
-}  // namespace aura