ui: Change ListModel to operate in size_t instead of int.

ui/app_list/app_list_model_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/app_list_model_view.h"
 
 #include <algorithm>
 
 #include "ui/app_list/app_list_item_view.h"
 #include "ui/app_list/app_list_model.h"
@@ skipping 118 matching lines @@
   if (index == selected_item_index_)
     SetSelectedItemByIndex(-1);
 }
 
 void AppListModelView::Update() {
   selected_item_index_ = -1;
   RemoveAllChildViews(true);
   if (!model_ || model_->item_count() == 0)
     return;
 
-  for (int i = 0; i < model_->item_count(); ++i)
+  for (size_t i = 0; i < model_->item_count(); ++i)
     AddChildView(new AppListItemView(this, model_->GetItemAt(i), listener_));
 
   Layout();
   SchedulePaint();
 }
 
 AppListItemView* AppListModelView::GetItemViewAtIndex(int index) {
   return static_cast<AppListItemView*>(child_at(index));
 }
 
@@ skipping 139 matching lines @@
   if (selected_item_index_ >= 0)
     handled = GetItemViewAtIndex(selected_item_index_)->OnKeyReleased(event);
 
   return handled;
 }
 
 void AppListModelView::OnPaintFocusBorder(gfx::Canvas* canvas) {
   // Override to not paint focus frame.
 }
 
-void AppListModelView::ListItemsAdded(int start, int count) {
-  for (int i = start; i < start + count; ++i) {
+void AppListModelView::ListItemsAdded(size_t start, size_t count) {
+  for (size_t i = start; i < start + count; ++i) {
     AddChildViewAt(new AppListItemView(this, model_->GetItemAt(i), listener_),
                    i);
   }
   Layout();
   SchedulePaint();
 }
 
-void AppListModelView::ListItemsRemoved(int start, int count) {
-  for (int i = 0; i < count; ++i)
+void AppListModelView::ListItemsRemoved(size_t start, size_t count) {
+  for (size_t i = 0; i < count; ++i)
     delete child_at(start);
 
   Layout();
   SchedulePaint();
 }
 
-void AppListModelView::ListItemsChanged(int start, int count) {
+void AppListModelView::ListItemsChanged(size_t start, size_t count) {
   NOTREACHED();
 }
 
 void AppListModelView::TotalPagesChanged() {
 }
 
 void AppListModelView::SelectedPageChanged(int old_selected, int new_selected) {
   Layout();
 }
 
 }  // namespace app_list