Move the concept of Activation to the Shell.

ui/aura/client/aura_constants.h

 // 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.
 
 #ifndef UI_AURA_CLIENT_AURA_CONSTANTS_H_
 #define UI_AURA_CLIENT_AURA_CONSTANTS_H_
 #pragma once
 
 #include "ui/aura/aura_export.h"
 
@@ skipping 26 matching lines @@
 // type of the value is |aura::DragDropClient*|.
 AURA_EXPORT extern const char kRootWindowDragDropClientKey[];
 
 // A property key to store the drag and drop delegate for a window. The type of
 // the value is |aura::WindowDragDropDelegate*|.
 AURA_EXPORT extern const char kDragDropDelegateKey[];
 
 // A property key to store the tooltip client for the root window. The type of
 // the value is |aura::TooltipClient*|.
 AURA_EXPORT extern const char kRootWindowTooltipClientKey[];
+
+// A property key to store what the client defines as the active window on the
+// RootWindow. The type of the value is |aura::Window*|.
+AURA_EXPORT extern const char kRootWindowActiveWindow[];
+
+// A property key to store a client that handles window activation. The type of
+// the value is |aura::ActivationClient*|.
+AURA_EXPORT extern const char kRootWindowActivationClient[];

[sky, 2011/12/09 23:11:23]

Can you clarify ownership of this and ActivationDelegateKey, both here and in
the header for the classes (maybe about see blah for details). Looks like both
are not owned by the window, so that the destructor should be made protected.

+
+// A property key to store the activation delegate for a window. The type of the
+// value is |aura::ActivationDelegate*|.
+AURA_EXPORT extern const char kActivationDelegateKey[];

[sky, 2011/12/09 23:11:23]

nit: would be nice if we sorted all the keys in this file.

+
 }  // namespace aura
 
 #endif  // UI_AURA_CLIENT_AURA_CONSTANTS_H_