Two changes to desktop aura for tooltips:

ui/views/widget/desktop_aura/scoped_tooltip_client.cc

+// 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.
+
+#include "ui/views/widget/desktop_aura/scoped_tooltip_client.h"
+
+#include "ui/aura/root_window.h"
+#include "ui/views/corewm/tooltip_controller.h"
+
+namespace views {
+
+// static
+corewm::TooltipController* ScopedTooltipClient::tooltip_controller_ = NULL;
+
+// static
+int ScopedTooltipClient::scoped_tooltip_client_count_ = 0;
+
+ScopedTooltipClient::ScopedTooltipClient(aura::RootWindow* root_window)
+    : root_window_(root_window) {
+  if (scoped_tooltip_client_count_++ == 0) {
+    tooltip_controller_ =
+        new corewm::TooltipController(gfx::SCREEN_TYPE_NATIVE);
+  }
+  aura::client::SetTooltipClient(root_window_, tooltip_controller_);
+  root_window_->AddPreTargetHandler(tooltip_controller_);
+}
+
+ScopedTooltipClient::~ScopedTooltipClient() {
+  root_window_->RemovePreTargetHandler(tooltip_controller_);
+  aura::client::SetTooltipClient(root_window_, NULL);
+  if (--scoped_tooltip_client_count_ == 0) {
+    delete tooltip_controller_;
+    tooltip_controller_ = NULL;
+  }
+}
+
+}  // namespace views