[win] Set the drag item visible when externally cancelling a drag in the app launcher

ui/app_list/views/apps_grid_view.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/app_list/views/apps_grid_view.h"
 
 #include <algorithm>
 #include <set>
 #include <string>
 
@@ skipping 252 matching lines @@
       // Make the drag view visible again.
       drag_view_->SetVisible(true);
       drag_view_->OnSyncDragEnd();
 
       grid_view_->EndDrag(canceled_ || !IsCursorWithinGridView());
     }
   }
 
   void EndDragExternally() {
     CancelDrag();
+    DCHECK(drag_view_);
+    drag_view_->SetVisible(true);
     drag_view_ = NULL;
   }
 
  private:
   // Overridden from ui::DragSourceWin.
   virtual void OnDragSourceCancel() OVERRIDE {
     canceled_ = true;
   }
 
   virtual void OnDragSourceDrop() OVERRIDE {
@@ skipping 1879 matching lines @@
 void AppsGridView::SetAsFolderDroppingTarget(const Index& target_index,
                                              bool is_target_folder) {
   AppListItemView* target_view =
       static_cast<AppListItemView*>(
           GetViewAtSlotOnCurrentPage(target_index.slot));
   if (target_view)
     target_view->SetAsAttemptedFolderTarget(is_target_folder);
 }
 
 }  // namespace app_list