Two changes to desktop aura for tooltips:

ui/views/widget/desktop_aura/scoped_tooltip_client.h

+// Copyright (c) 2013 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_VIEWS_WIDGET_DESKTOP_AURA_SCOPED_TOOLTIP_CLIENT_H_
+#define UI_VIEWS_WIDGET_DESKTOP_AURA_SCOPED_TOOLTIP_CLIENT_H_
+
+#include "base/basictypes.h"
+
+namespace aura {
+class RootWindow;
+}
+
+namespace views {
+
+namespace corewm {
+class TooltipController;
+}
+
+// ScopedTooltipClient is responsible for installing a TooltipClient
+// implementation on a RootWindow. Additionally it ensures only one
+// TooltipController is only ever created. In this way all
+// DesktopNativeWidgetAuras share the same TooltipClient.
+class ScopedTooltipClient {
+ public:
+  explicit ScopedTooltipClient(aura::RootWindow* root_window);
+  ~ScopedTooltipClient();
+
+ private:
+  // Single TooltipController.
+  static corewm::TooltipController* tooltip_controller_;
+
+  // Number of ScopedTooltipClients created.
+  static int scoped_tooltip_client_count_;
+
+  aura::RootWindow* root_window_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedTooltipClient);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_SCOPED_TOOLTIP_CLIENT_H_