App list uses PaginationModel to transition between pages.

ui/app_list/views/app_list_view_unittest.cc

Index: ui/app_list/views/app_list_view_unittest.cc
diff --git a/ui/app_list/views/app_list_view_unittest.cc b/ui/app_list/views/app_list_view_unittest.cc
index ef39edd41ce21996e0054222cdf212ea04e73273..1b7a41718be8f20521e726197d584784d7a3fcc5 100644
--- a/ui/app_list/views/app_list_view_unittest.cc
+++ b/ui/app_list/views/app_list_view_unittest.cc
@@ -292,6 +292,7 @@ void AppListViewTestContext::RunStartPageTest() {
     EXPECT_FALSE(IsViewAtOrigin(contents_view->apps_container_view()));
     EXPECT_EQ(3u, GetVisibleTileItemViews(start_page_view->tile_views()));
 
+    contents_view->FinishCurrentAnimationForTests();

[calamity, 2014/06/12 03:26:54]

If Layout() sets everything to "where it ends up", shouldn't all animations be
cancelled on Layout()?

[Matt Giuca, 2014/06/16 07:20:28]

Good point. They previously weren't. Now Layout does end all animations, so we
don't need FinishCurrentAnimationForTests.

Note that I had to rewrite Layout to use completely different code to
UpdatePageBounds, since we need to move ALL the pages out of the way, not just
the current begin and end page (because there could be a three-way animation, it
isn't enough to just move the begin and end pages).

     contents_view->SetActivePage(
         contents_view->GetPageIndexForNamedPage(ContentsView::NAMED_PAGE_APPS));
     contents_view->Layout();