Add focus rules for Ash.

ash/wm/ash_focus_rules.h

Index: ash/wm/ash_focus_rules.h
===================================================================
--- ash/wm/ash_focus_rules.h	(revision 0)
+++ ash/wm/ash_focus_rules.h	(revision 0)
@@ -0,0 +1,36 @@
+// Copyright (c) 2012 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 ASH_WM_ASH_FOCUS_RULES_H_
+#define ASH_WM_ASH_FOCUS_RULES_H_
+
+#include "ash/ash_export.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "ui/views/corewm/focus_rules.h"
+
+namespace ash {
+namespace wm {
+
+class ASH_EXPORT AshFocusRules : public views::corewm::FocusRules {
+ public:
+  AshFocusRules();
+  virtual ~AshFocusRules();
+
+ private:
+  // Overridden from views::corewm::FocusRules:
+  virtual bool CanActivateWindow(aura::Window* window) OVERRIDE;
+  virtual bool CanFocusWindow(aura::Window* window) OVERRIDE;
+  virtual aura::Window* GetActivatableWindow(aura::Window* window) OVERRIDE;
+  virtual aura::Window* GetFocusableWindow(aura::Window* window) OVERRIDE;
+  virtual aura::Window* GetNextActivatableWindow(aura::Window* ignore) OVERRIDE;
+  virtual aura::Window* GetNextFocusableWindow(aura::Window* ignore) OVERRIDE;
+
+  DISALLOW_COPY_AND_ASSIGN(AshFocusRules);
+};
+
+}  // namespace wm
+}  // namespace ash
+
+#endif  // ASH_WM_ASH_FOCUS_RULES_H_