Turn ScalableAppList on by default

Test fixes:
AppListPresenterDelegateZeroStateTest.ClickSearchBoxInTabletMode
*   test was incorrectly calculating search box bounds in midst of
    an animation - fixed by making animations non zero length after
    initial test state was set up

AppListModelFolderTest.FolderItem
*   tests behavior expected when the feature is off

AppListViewTest.AppsGridViewVisibilityOnReopening
*   with the new feature, apps grid is shown faded in the background
    on search results page - updated the expectation

BUG=976947,976954

Change-Id: Ia571dc6026b5d0c0dd512e6dc69e2d22492343ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1838928
Commit-Queue: Toni Baržić <tbarzic@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702943}

ash/app_list/app_list_presenter_delegate_unittest.cc

@@ -330,15 +330,16 @@ TEST_F(AppListPresenterDelegateZeroStateTest,
 // Verifies that tapping on the search box in tablet mode with animation and
 // zero state enabled should not bring Chrome crash (https://crbug.com/958267).
 TEST_F(AppListPresenterDelegateZeroStateTest, ClickSearchBoxInTabletMode) {
+  EnableTabletMode(true);
+  GetAppListTestHelper()->ShowAndRunLoop(GetPrimaryDisplayId());
+  GetAppListTestHelper()->CheckState(AppListViewState::kFullscreenAllApps);
+
   // Necessary for AppListView::StateAnimationMetricsReporter::Report being
   // called when animation ends.
   ui::ScopedAnimationDurationScaleMode non_zero_duration_mode(
       ui::ScopedAnimationDurationScaleMode::NON_ZERO_DURATION);
   app_list::AppListView::SetShortAnimationForTesting(false);
 
-  EnableTabletMode(true);
-  GetAppListTestHelper()->ShowAndRunLoop(GetPrimaryDisplayId());
-  GetAppListTestHelper()->CheckState(AppListViewState::kFullscreenAllApps);
   ui::test::EventGenerator* generator = GetEventGenerator();
 
   // Gesture tap on the search box.

ash/app_list/model/app_list_model_unittest.cc

@@ -229,6 +229,9 @@ TEST_F(AppListModelTest, AppOrder) {
 using AppListModelFolderTest = AppListModelTest;
 
 TEST_F(AppListModelFolderTest, FolderItem) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitWithFeatures({},
+                                       {app_list_features::kScalableAppList});
   AppListFolderItem* folder = new AppListFolderItem("folder1");
   const size_t num_folder_apps = 8;
   const size_t num_observed_apps = 4;

ash/app_list/views/app_list_view_unittest.cc

@@ -2154,7 +2154,8 @@ TEST_F(AppListViewTest, AppsGridViewVisibilityOnReopening) {
 
   view_->SetState(ash::AppListViewState::kFullscreenSearch);
   SetAppListState(ash::AppListState::kStateSearchResults);
-  EXPECT_FALSE(IsViewVisibleOnScreen(apps_grid_view()));
+  EXPECT_EQ(app_list_features::IsScalableAppListEnabled(),
+            IsViewVisibleOnScreen(apps_grid_view()));
 
   // Close the app-list and re-show to fullscreen all apps.
   view_->SetState(ash::AppListViewState::kClosed);

ash/public/cpp/app_list/app_list_features.cc

@@ -44,7 +44,7 @@ const base::Feature kEnableSearchBoxSelection{"EnableSearchBoxSelection",
 const base::Feature kEnableAggregatedMlAppRanking{
     "EnableAggregatedMlAppRanking", base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kScalableAppList{"ScalableAppList",
-                                     base::FEATURE_DISABLED_BY_DEFAULT};
+                                     base::FEATURE_ENABLED_BY_DEFAULT};
 const base::Feature kEnableFuzzyAppSearch{"EnableFuzzyAppSearch",
                                           base::FEATURE_DISABLED_BY_DEFAULT};