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

ui/views/corewm/tooltip_controller.h

 // 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 UI_VIEWS_COREWM_TOOLTIP_CONTROLLER_H_
 #define UI_VIEWS_COREWM_TOOLTIP_CONTROLLER_H_
 
 #include <map>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 20 matching lines @@
 
 // TooltipController provides tooltip functionality for aura.
 class VIEWS_EXPORT TooltipController : public aura::client::TooltipClient,
                                        public ui::EventHandler,
                                        public aura::WindowObserver {
  public:
   explicit TooltipController(scoped_ptr<Tooltip> tooltip);
   virtual ~TooltipController();
 
   // Overridden from aura::client::TooltipClient.
-  virtual void UpdateTooltip(aura::Window* target) OVERRIDE;
+  virtual void UpdateTooltip(aura::Window* target,
+                             bool force) OVERRIDE;
   virtual void SetTooltipShownTimeout(aura::Window* target,
                                       int timeout_in_ms) OVERRIDE;
   virtual void SetTooltipsEnabled(bool enable) OVERRIDE;
 
   // Overridden from ui::EventHandler.
   virtual void OnKeyEvent(ui::KeyEvent* event) OVERRIDE;
   virtual void OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
   virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
   virtual void OnCancelMode(ui::CancelModeEvent* event) OVERRIDE;
 
   // Overridden from aura::WindowObserver.
   virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
 
   const gfx::Point& mouse_location() const { return curr_mouse_loc_; }
 
  private:
   friend class test::TooltipControllerTestHelper;
 
   void TooltipTimerFired();
   void TooltipShownTimerFired();
 
   // Updates the tooltip if required (if there is any change in the tooltip
-  // text or the aura::Window.
-  void UpdateIfRequired();
+  // text or the aura::Window). If |force| is true the tooltip will be updated
+  // regardless of these conditions.
+  void UpdateIfRequired(bool force);
 
   // Only used in tests.
   bool IsTooltipVisible();
 
   bool IsDragDropInProgress();
 
   // Returns true if the cursor is visible.
   bool IsCursorVisible();
 
   int GetTooltipShownTimeout();
@@ skipping 25 matching lines @@
 
   std::map<aura::Window*, int> tooltip_shown_timeout_map_;
 
   DISALLOW_COPY_AND_ASSIGN(TooltipController);
 };
 
 }  // namespace corewm
 }  // namespace views
 
 #endif  // UI_VIEWS_COREWM_TOOLTIP_CONTROLLER_H_