Fix bug 105043: Panels [WIN]: For minimize panels, taskbar hover preview show the 4-pixel represent…

chrome/browser/ui/panels/panel.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 "chrome/browser/ui/panels/panel.h"
 
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
@@ skipping 195 matching lines @@
 }
 
 void Panel::SetPreviewMode(bool in_preview) {
   DCHECK_NE(in_preview_mode_, in_preview);
   in_preview_mode_ = in_preview;
 }
 
 void Panel::SetExpansionState(ExpansionState new_state) {
   if (expansion_state_ == new_state)
     return;
+  native_panel_->PanelExpansionStateChanging(expansion_state_, new_state);
   expansion_state_ = new_state;
 
   manager()->OnPanelExpansionStateChanged(this);
 
   DCHECK(initialized_ && panel_strip_ != NULL);
   native_panel_->PreventActivationByOS(panel_strip_->IsPanelMinimized(this));
   UpdateMinimizeRestoreButtonVisibility();
 
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_PANEL_CHANGED_EXPANSION_STATE,
@@ skipping 562 matching lines @@
   max_size_policy_ = CUSTOM_MAX_SIZE;
 }
 
 void Panel::OnPanelEndUserResizing() {
   SetPreviewMode(false);
 }
 
 void Panel::DestroyBrowser() {
   native_panel_->DestroyPanelBrowser();
 }