Fixes bug where tooltips would get stuck. This was happening because...

chrome/views/aero_tooltip_manager.cc

 // Copyright (c) 2006-2008 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 <windows.h>
 #include <atlbase.h>
 #include <atlapp.h>  // for GET_X/Y_LPARAM
 #include <commctrl.h>
 #include <shlobj.h>
 
@@ skipping 40 matching lines @@
     }
     initial_timer_ = new InitialTimer(this, initial_delay_);
   } else {
     // Hide the tooltip and cancel any timers.
     ::SendMessage(tooltip_hwnd_, TTM_POP, 0, 0);
     ::SendMessage(tooltip_hwnd_, TTM_TRACKACTIVATE, false, (LPARAM)&toolinfo_);
     return;
   }
 }
 
+void AeroTooltipManager::OnMouseLeave() {
+  last_mouse_x_ = last_mouse_y_ = -1;
+  UpdateTooltip();
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // AeroTooltipManager, private:
 
 void AeroTooltipManager::Init() {
   // Create the tooltip control.
   tooltip_hwnd_ = CreateWindowEx(
       WS_EX_TRANSPARENT | l10n_util::GetExtendedTooltipStyles(),
       TOOLTIPS_CLASS, NULL, TTS_NOPREFIX, 0, 0, 0, 0,
       parent_, NULL, NULL, NULL);
   // Add one tool that is used for all tooltips.
@@ skipping 41 matching lines @@
   manager_ = NULL;
 }
 
 void AeroTooltipManager::InitialTimer::Execute() {
   if (manager_)
     manager_->OnTimer();
 }
 
 }  // namespace views