Fix app list item indexing bug.

ui/app_list/views/search_result_list_view_unittest.cc

 // Copyright 2014 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/search_result_list_view.h"
 
 #include <stddef.h>
 
 #include <map>
 
@@ skipping 60 matching lines @@
         result->set_details(base::ASCIIToUTF16("Detail"));
       results->Add(std::move(result));
     }
 
     // Adding results will schedule Update().
     RunPendingMessages();
     view_->OnContainerSelected(false, false);
   }
 
   int GetOpenResultCountAndReset(int ranking) {
+    EXPECT_GT(view_delegate_.open_search_result_counts().count(ranking), 0u);
     int result = view_delegate_.open_search_result_counts()[ranking];
     view_delegate_.open_search_result_counts().clear();
     return result;
   }
 
   int GetResultCount() { return view_->num_results(); }
 
   int GetSelectedIndex() { return view_->selected_index(); }
 
   void ResetSelectedIndex() {
@@ skipping 157 matching lines @@
   EXPECT_EQ(0.0f, GetProgressBarAt(0)->current_value());
   GetResults()->GetItemAt(0)->SetPercentDownloaded(10);
 
   DeleteResultAt(0);
   RunPendingMessages();
   EXPECT_EQ(0.0f, GetProgressBarAt(0)->current_value());
 }
 
 }  // namespace test
 }  // namespace app_list