Fix crash on item drag in shelf.

chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.cc

 // Copyright 2013 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/ash/launcher/chrome_launcher_controller_impl.h"
 
 #include <stddef.h>
 
 #include <vector>
 
@@ skipping 1159 matching lines @@
     return;
 
   const int max_index = model_->item_count();
   const int index = model_->ItemIndexByID(shelf_id);
   DCHECK_GT(index, 0);
 
   const std::string& app_id = GetAppIDForShelfID(shelf_id);
   DCHECK(!app_id.empty());
 
   std::string app_id_before;
-  std::string app_id_after;
+  std::vector<std::string> app_ids_after;
 
   for (int i = index - 1; i > 0; --i) {
     const ash::ShelfID shelf_id_before = model_->items()[i].id;
     if (IsPinned(shelf_id_before)) {
       app_id_before = GetAppIDForShelfID(shelf_id_before);
       DCHECK(!app_id_before.empty());
       break;
     }
   }
 
   for (int i = index + 1; i < max_index; ++i) {
     const ash::ShelfID shelf_id_after = model_->items()[i].id;
     if (IsPinned(shelf_id_after)) {
-      app_id_after = GetAppIDForShelfID(shelf_id_after);
+      const std::string app_id_after = GetAppIDForShelfID(shelf_id_after);
       DCHECK(!app_id_after.empty());
-      break;
+      app_ids_after.push_back(app_id_after);
     }
   }
 
-  ash::launcher::SetPinPosition(profile_, app_id, app_id_before, app_id_after);
+  ash::launcher::SetPinPosition(profile_, app_id, app_id_before, app_ids_after);
 }
 
 void ChromeLauncherControllerImpl::OnSyncModelUpdated() {
   UpdateAppLaunchersFromPref();
 }
 
 void ChromeLauncherControllerImpl::ScheduleUpdateAppLaunchersFromPref() {
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,
       base::Bind(&ChromeLauncherControllerImpl::UpdateAppLaunchersFromPref,
@@ skipping 508 matching lines @@
     if (index == -1)
       continue;
     ash::ShelfItem item = model_->items()[index];
     item.image = image;
     if (arc_deferred_launcher_)
       arc_deferred_launcher_->MaybeApplySpinningEffect(id, &item.image);
     model_->Set(index, item);
     // It's possible we're waiting on more than one item, so don't break.
   }
 }