Aura tooltips do not move on mouse move in case of many neighboring views with the same label

ui/wm/public/tooltip_client.cc

 // 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.
 
 #include "ui/wm/public/tooltip_client.h"
 
 #include "ui/aura/window.h"
 #include "ui/aura/window_property.h"
 
 DECLARE_WINDOW_PROPERTY_TYPE(aura::client::TooltipClient*)
 DECLARE_WINDOW_PROPERTY_TYPE(base::string16*)
+DECLARE_WINDOW_PROPERTY_TYPE(void**)
 
 namespace aura {
 namespace client {
 
 DEFINE_LOCAL_WINDOW_PROPERTY_KEY(
     TooltipClient*, kRootWindowTooltipClientKey, NULL);
 DEFINE_LOCAL_WINDOW_PROPERTY_KEY(base::string16*, kTooltipTextKey, NULL);
+DEFINE_LOCAL_WINDOW_PROPERTY_KEY(void*, kTooltipIdKey, NULL);
 
 void SetTooltipClient(Window* root_window, TooltipClient* client) {
   DCHECK_EQ(root_window->GetRootWindow(), root_window);
   root_window->SetProperty(kRootWindowTooltipClientKey, client);
 }
 
 TooltipClient* GetTooltipClient(Window* root_window) {
   if (root_window)
     DCHECK_EQ(root_window->GetRootWindow(), root_window);
   return root_window ?
       root_window->GetProperty(kRootWindowTooltipClientKey) : NULL;
 }
 
 void SetTooltipText(Window* window, base::string16* tooltip_text) {
   window->SetProperty(kTooltipTextKey, tooltip_text);
+  window->SetProperty(kTooltipIdKey, static_cast<void*>(NULL));

[sky, 2014/06/02 15:39:47]

Is this really necessary?

+}
+
+void UpdateTooltipId(Window* window, void* id) {
+  window->SetProperty(kTooltipIdKey, id);
 }
 
 const base::string16 GetTooltipText(Window* window) {
   base::string16* string_ptr = window->GetProperty(kTooltipTextKey);
   return string_ptr ? *string_ptr : base::string16();
 }
 
+const void* GetTooltipId(Window* window) {
+  return window->GetProperty(kTooltipIdKey);
+}
+
 }  // namespace client
 }  // namespace aura