ui: Do not expose the underline type (vector) used in ListModel.

ui/base/models/list_model_unittest.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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/base/models/list_model.h"
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 63 matching lines @@
   ExpectCountsEqual(2, 0, 0);
 
   // Insert FooItem(2) at position 0
   model.AddAt(0, new FooItem(2));
   ExpectCountsEqual(3, 0, 0);
 
   // Total 3 items in mode.
   EXPECT_EQ(3, model.item_count());
 
   // First one should be FooItem(2), followed by FooItem(0) and FooItem(1)
-  EXPECT_EQ(2, model.item_at(0)->id());
-  EXPECT_EQ(0, model.item_at(1)->id());
-  EXPECT_EQ(1, model.item_at(2)->id());
+  EXPECT_EQ(2, model.GetItemAt(0)->id());
+  EXPECT_EQ(0, model.GetItemAt(1)->id());
+  EXPECT_EQ(1, model.GetItemAt(2)->id());
 }
 
 TEST_F(ListModelTest, Remove) {
   ListModel<FooItem> model;
   model.AddObserver(this);
 
   model.Add(new FooItem(0));
   model.Add(new FooItem(1));
   model.Add(new FooItem(2));
 
   ClearCounts();
 
   // Remove item at index 1 from model and release memory.
   model.DeleteAt(1);
   ExpectCountsEqual(0, 1, 0);
 
   EXPECT_EQ(2, model.item_count());
-  EXPECT_EQ(0, model.item_at(0)->id());
-  EXPECT_EQ(2, model.item_at(1)->id());
+  EXPECT_EQ(0, model.GetItemAt(0)->id());
+  EXPECT_EQ(2, model.GetItemAt(1)->id());
 
   // Remove all items from model and delete them.
   model.DeleteAll();
   ExpectCountsEqual(0, 3, 0);
 }
 
 TEST_F(ListModelTest, RemoveAll) {
   ListModel<FooItem> model;
   model.AddObserver(this);
 
@@ skipping 23 matching lines @@
   ClearCounts();
 
   model.NotifyItemsChanged(0, 1);
   ExpectCountsEqual(0, 0, 1);
 
   model.NotifyItemsChanged(1, 2);
   ExpectCountsEqual(0, 0, 3);
 }
 
 }  // namespace ui