Introduce performance test of app-list's page transition smoothness

This CL adds the tests for the animation smoothness of the page
transition between the apps grid in the list.

I ran this for 5 times on nocturne, here's the result;
next-page / clamshell: 73, 80, 73, 46, 46
next-page / tablet: 86, 66, 86, 6, 86
page-jump / clamshell: 40, 80, 26, 26, 40
page-jump / tablet: 73, 40, 66, 6, 86

Bug: 970879
Test: interactive_ui_tests
Change-Id: Ibc519b0cf47e3540d9a2c57f521ed64ee981c572
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1643783Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Jun Mukai <mukai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#666395}

ash/public/cpp/test/shell_test_api.h

@@ -21,6 +21,7 @@ enum class AppListViewState;
 class DragDropController;
 class MessageCenterController;
 class NativeCursorManagerAsh;
+class PaginationModel;
 class PowerPrefs;
 class ScreenPositionController;
 class Shell;
@@ -94,6 +95,10 @@ class ASH_EXPORT ShellTestApi {
   // state transition animation.
   void WaitForLauncherAnimationState(AppListViewState state);
 
+  // Returns the pagination model of the currently visible app-list view.
+  // It returns nullptr when app-list is not shown.
+  PaginationModel* GetAppListPaginationModel();
+
   // Returns the list of windows used in overview item. Returns empty
   // if not in the overview mode.
   std::vector<aura::Window*> GetItemWindowListInOverviewGrids();

ash/shell_test_api.cc

@@ -10,6 +10,7 @@
 #include "ash/accelerators/accelerator_commands.h"
 #include "ash/accelerometer/accelerometer_reader.h"
 #include "ash/app_list/app_list_controller_impl.h"
+#include "ash/app_list/presenter/app_list_presenter_impl.h"
 #include "ash/app_list/views/app_list_view.h"
 #include "ash/keyboard/ash_keyboard_controller.h"
 #include "ash/public/cpp/app_list/app_list_types.h"
@@ -250,6 +251,14 @@ void ShellTestApi::WaitForLauncherAnimationState(
   run_loop.Run();
 }
 
+PaginationModel* ShellTestApi::GetAppListPaginationModel() {
+  app_list::AppListView* view =
+      Shell::Get()->app_list_controller()->presenter()->GetView();
+  if (!view)
+    return nullptr;
+  return view->GetAppsPaginationModel();
+}
+
 std::vector<aura::Window*> ShellTestApi::GetItemWindowListInOverviewGrids() {
   return ash::Shell::Get()
       ->overview_controller()

chrome/browser/ui/ash/launcher_page_switches_interactive_uitest.cc

+// Copyright 2019 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 "ash/public/cpp/app_list/app_list_types.h"
+#include "ash/public/cpp/pagination/pagination_model.h"
+#include "ash/public/cpp/pagination/pagination_model_observer.h"
+#include "ash/public/cpp/test/shell_test_api.h"
+#include "base/run_loop.h"
+#include "base/task/post_task.h"
+#include "chrome/browser/ui/app_list/test/chrome_app_list_test_support.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/views/frame/browser_view.h"
+#include "chrome/test/base/perf/performance_test.h"
+#include "ui/base/test/ui_controls.h"
+
+namespace {
+
+class PageSwitchWaiter : public ash::PaginationModelObserver {
+ public:
+  explicit PageSwitchWaiter(ash::PaginationModel* model) : model_(model) {
+    model_->AddObserver(this);
+  }
+  ~PageSwitchWaiter() override { model_->RemoveObserver(this); }
+
+  void Wait() { run_loop_.Run(); }
+
+ private:
+  // ash::PaginationModelObserver:
+  void TransitionEnded() override { run_loop_.Quit(); }
+
+  ash::PaginationModel* model_;
+  base::RunLoop run_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(PageSwitchWaiter);
+};
+
+}  // namespace
+
+class LauncherPageSwitchesTest : public UIPerformanceTest,
+                                 public ::testing::WithParamInterface<bool> {
+ public:
+  LauncherPageSwitchesTest() = default;
+  ~LauncherPageSwitchesTest() override = default;
+
+  // UIPerformanceTest:
+  void SetUpOnMainThread() override {
+    UIPerformanceTest::SetUpOnMainThread();
+    is_tablet_mode_ = GetParam();
+
+    test::PopulateDummyAppListItems(100);
+    if (base::SysInfo::IsRunningOnChromeOS()) {
+      base::RunLoop run_loop;
+      base::PostDelayedTask(FROM_HERE, run_loop.QuitClosure(),
+                            base::TimeDelta::FromSeconds(5));
+      run_loop.Run();
+    }
+
+    ash::ShellTestApi shell_test_api;
+
+    // switch to tablet-mode if necessary.
+    if (is_tablet_mode_)
+      shell_test_api.EnableTabletModeWindowManager(true);
+
+    // Open the fullscreen app; required for page switching.
+    BrowserView* browser_view =
+        BrowserView::GetBrowserViewForBrowser(browser());
+    aura::Window* browser_window = browser_view->GetWidget()->GetNativeWindow();
+    ui_controls::SendKeyPress(browser_window, ui::VKEY_BROWSER_SEARCH,
+                              /*control=*/false,
+                              /*shift=*/true,
+                              /*alt=*/false,
+                              /* command = */ false);
+    shell_test_api.WaitForLauncherAnimationState(
+        ash::AppListViewState::kFullscreenAllApps);
+  }
+
+  // UIPerformanceTest:
+  std::vector<std::string> GetUMAHistogramNames() const override {
+    return {
+        is_tablet_mode_
+            ? "Apps.PaginationTransition.AnimationSmoothness.TabletMode"
+            : "Apps.PaginationTransition.AnimationSmoothness.ClamshellMode",
+    };
+  }
+
+ private:
+  bool is_tablet_mode_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(LauncherPageSwitchesTest);
+};
+
+IN_PROC_BROWSER_TEST_P(LauncherPageSwitchesTest, SwitchToNextPage) {
+  ash::PaginationModel* model = ash::ShellTestApi().GetAppListPaginationModel();
+  ASSERT_TRUE(model);
+  EXPECT_LT(1, model->total_pages());
+  EXPECT_EQ(0, model->selected_page());
+
+  PageSwitchWaiter waiter(model);
+  model->SelectPageRelative(1, /*animate=*/true);
+  waiter.Wait();
+}
+
+IN_PROC_BROWSER_TEST_P(LauncherPageSwitchesTest, SwitchToFarPage) {
+  ash::PaginationModel* model = ash::ShellTestApi().GetAppListPaginationModel();
+  ASSERT_TRUE(model);
+  EXPECT_LT(2, model->total_pages());
+  EXPECT_EQ(0, model->selected_page());
+
+  PageSwitchWaiter waiter(model);
+  model->SelectPageRelative(2, /*animate=*/true);
+  waiter.Wait();
+}
+
+INSTANTIATE_TEST_SUITE_P(,
+                         LauncherPageSwitchesTest,
+                         /*tablet_mode=*/::testing::Bool());

chrome/test/BUILD.gn

@@ -5417,6 +5417,7 @@ if (!is_android) {
         "../browser/ui/ash/drag_to_overview_interactive_uitest.cc",
         "../browser/ui/ash/launcher_animations_interactive_uitest.cc",
         "../browser/ui/ash/launcher_drag_interactive_uitest.cc",
+        "../browser/ui/ash/launcher_page_switches_interactive_uitest.cc",
         "../browser/ui/ash/overview_animations_interactive_uitest.cc",
         "../browser/ui/ash/overview_window_drag_interactive_uitest.cc",
         "../browser/ui/ash/screen_rotation_interactive_uitest.cc",