Do not display the tab switcher until the tab models are restored.

If tab models are restored while the overview is visible, update the
tab switcher with the updated list.

R=wychen@chromium.org

Bug: 990982, 955436
Change-Id: Ia7c63e35624dd37cd7ff0063727ba64d040fe3ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1769298Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
Reviewed-by: Mei Liang <meiliang@chromium.org>
Commit-Queue: Matt Simmons <mattsimmons@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697858}

chrome/android/features/start_surface/internal/javatests/src/org/chromium/chrome/features/start_surface/StartSurfaceLayoutPerfTest.java

@@ -106,6 +106,12 @@ public class StartSurfaceLayoutPerfTest {
             mTabNumCap = 0;
         }
         assertTrue(FeatureUtilities.isTabToGtsAnimationEnabled());
+
+        CriteriaHelper.pollUiThread(Criteria.equals(true,
+                mActivityTestRule.getActivity()
+                        .getTabModelSelector()
+                        .getTabModelFilterProvider()
+                        .getCurrentTabModelFilter()::isTabModelRestored));
     }
 
     @Test

chrome/android/features/start_surface/internal/javatests/src/org/chromium/chrome/features/start_surface/StartSurfaceLayoutTest.java

@@ -4,6 +4,10 @@
 
 package org.chromium.chrome.features.start_surface;
 
+import static android.support.test.espresso.Espresso.onView;
+import static android.support.test.espresso.action.ViewActions.click;
+import static android.support.test.espresso.matcher.ViewMatchers.withId;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
@@ -17,15 +21,16 @@ import android.animation.ValueAnimator;
 import android.graphics.Bitmap;
 import android.os.Build;
 import android.provider.Settings;
+import android.support.annotation.Nullable;
 import android.support.test.InstrumentationRegistry;
-import android.support.test.espresso.Espresso;
-import android.support.test.espresso.action.ViewActions;
+import android.support.test.espresso.NoMatchingViewException;
+import android.support.test.espresso.ViewAssertion;
 import android.support.test.espresso.contrib.RecyclerViewActions;
-import android.support.test.espresso.matcher.ViewMatchers;
 import android.support.test.filters.MediumTest;
+import android.support.test.filters.SmallTest;
+import android.support.v7.widget.RecyclerView;
 import android.text.TextUtils;
-
-import androidx.annotation.Nullable;
+import android.view.View;
 
 import org.junit.Assert;
 import org.junit.Before;
@@ -75,7 +80,6 @@ import java.util.List;
         "force-fieldtrials=Study/Group"})
 @Restriction(UiRestriction.RESTRICTION_TYPE_PHONE)
 public class StartSurfaceLayoutTest {
-    private static final String TAG = "SSLayoutTest";
     private static final String BASE_PARAMS = "force-fieldtrial-params="
             + "Study.Group:soft-cleanup-delay/0/cleanup-delay/0/skip-slow-zooming/false"
             + "/zooming-min-sdk-version/19/zooming-min-memory-mb/512";
@@ -96,6 +100,7 @@ public class StartSurfaceLayoutTest {
     @Before
     public void setUp() throws InterruptedException {
         FeatureUtilities.setGridTabSwitcherEnabledForTesting(true);
+
         EmbeddedTestServer testServer =
                 EmbeddedTestServer.createAndStartServer(InstrumentationRegistry.getContext());
         mActivityTestRule.startMainActivityFromLauncher();
@@ -113,6 +118,12 @@ public class StartSurfaceLayoutTest {
 
         mActivityTestRule.getActivity().getTabContentManager().setCaptureMinRequestTimeForTesting(
                 0);
+
+        CriteriaHelper.pollUiThread(Criteria.equals(true,
+                mActivityTestRule.getActivity()
+                        .getTabModelSelector()
+                        .getTabModelFilterProvider()
+                        .getCurrentTabModelFilter()::isTabModelRestored));
     }
 
     @Test
@@ -340,8 +351,9 @@ public class StartSurfaceLayoutTest {
             if (mActivityTestRule.getActivity()
                             .getTabContentManager()
                             .getPendingReadbacksForTesting()
-                    > 0)
+                    > 0) {
                 break;
+            }
 
             // Restart Chrome.
             // Although we're destroying the activity, the Application will still live on since its
@@ -415,9 +427,8 @@ public class StartSurfaceLayoutTest {
                 waitForCaptureRateControl();
             }
             int count = getCaptureCount();
-            Espresso.onView(ViewMatchers.withId(org.chromium.chrome.tab_ui.R.id.tab_list_view))
-                    .perform(RecyclerViewActions.actionOnItemAtPosition(
-                            targetIndex, ViewActions.click()));
+            onView(withId(org.chromium.chrome.tab_ui.R.id.tab_list_view))
+                    .perform(RecyclerViewActions.actionOnItemAtPosition(targetIndex, click()));
             CriteriaHelper.pollUiThread(() -> {
                 boolean doneHiding =
                         !mActivityTestRule.getActivity().getLayoutManager().overviewVisible();
@@ -532,14 +543,57 @@ public class StartSurfaceLayoutTest {
         Assert.assertEquals(0, mAllBitmaps.size() - count);
     }
 
+    @Test
+    @SmallTest
+    @CommandLineFlags.Add({BASE_PARAMS})
+    public void testIncognitoEnterGts() throws Exception {
+        mActivityTestRule.newIncognitoTabFromMenu();
+        onView(withId(org.chromium.chrome.R.id.tab_switcher_button)).perform(click());
+
+        onView(withId(org.chromium.chrome.tab_ui.R.id.tab_list_view))
+                .check(TabCountAssertion.havingTabCount(1));
+
+        onView(withId(org.chromium.chrome.tab_ui.R.id.tab_list_view))
+                .perform(RecyclerViewActions.actionOnItemAtPosition(0, click()));
+
+        CriteriaHelper.pollInstrumentationThread(
+                () -> !mActivityTestRule.getActivity().getLayoutManager().overviewVisible());
+
+        onView(withId(org.chromium.chrome.R.id.tab_switcher_button)).perform(click());
+
+        onView(withId(org.chromium.chrome.tab_ui.R.id.tab_list_view))
+                .check(TabCountAssertion.havingTabCount(1));
+    }
+
+    private static class TabCountAssertion implements ViewAssertion {
+        private int mExpectedCount;
+
+        public static TabCountAssertion havingTabCount(int tabCount) {
+            return new TabCountAssertion(tabCount);
+        }
+
+        public TabCountAssertion(int expectedCount) {
+            mExpectedCount = expectedCount;
+        }
+
+        @Override
+        public void check(View view, NoMatchingViewException noMatchException) {
+            if (noMatchException != null) throw noMatchException;
+
+            RecyclerView.Adapter adapter = ((RecyclerView) view).getAdapter();
+            assertEquals(mExpectedCount, adapter.getItemCount());
+        }
+    }
+
     private void enterGTS() throws InterruptedException {
         Tab currentTab = mActivityTestRule.getActivity().getTabModelSelector().getCurrentTab();
         // Native tabs need to be invalidated first to trigger thumbnail taking, so skip them.
         boolean checkThumbnail = !currentTab.isNativePage();
 
-        if (checkThumbnail)
+        if (checkThumbnail) {
             mActivityTestRule.getActivity().getTabContentManager().removeTabThumbnail(
                     currentTab.getId());
+        }
 
         int count = getCaptureCount();
         waitForCaptureRateControl();

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_groups/TabGroupModelFilter.java

@@ -101,7 +101,7 @@ public class TabGroupModelFilter extends TabModelFilter {
      * group.
      */
     private class TabGroup {
-        private final static int INVALID_GROUP_ID = -1;
+        private static final int INVALID_GROUP_ID = -1;
         private final Set<Integer> mTabIds;
         private int mLastShownTabId;
         private int mGroupId;
@@ -174,7 +174,6 @@ public class TabGroupModelFilter extends TabModelFilter {
     private int mActualGroupCount;
     private Tab mAbsentSelectedTab;
     private boolean mShouldRecordUma = true;
-    private boolean mTabRestoreCompleted;
     private boolean mIsResetting;
 
     public TabGroupModelFilter(TabModel tabModel) {
@@ -188,7 +187,6 @@ public class TabGroupModelFilter extends TabModelFilter {
                 RecordHistogram.recordCountHistogram("TabGroups.UserGroupCount", mActualGroupCount);
                 Tab currentTab = TabModelUtils.getCurrentTab(getTabModel());
                 if (currentTab != null) recordSessionsCount(currentTab);
-                mTabRestoreCompleted = true;
                 removeObserver(this);
             }
         });
@@ -654,7 +652,7 @@ public class TabGroupModelFilter extends TabModelFilter {
     public void didMoveTab(Tab tab, int newIndex, int curIndex) {
         // Ignore didMoveTab calls in tab restoring stage. For incognito mode, bypass this check
         // since there is no restoring stage.
-        if (!mTabRestoreCompleted && !isIncognito()) return;
+        if (!isTabModelRestored()) return;
         // Need to cache the flags before resetting the internal data map.
         boolean isMergeTabToGroup = isMergeTabToGroup(tab);
         boolean isMoveTabOutOfGroup = isMoveTabOutOfGroup(tab);

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabListMediator.java

@@ -739,7 +739,13 @@ class TabListMediator {
      * The selected border should re-appear in the final fading-in stage.
      */
     void prepareOverview() {
-        if (!FeatureUtilities.isTabToGtsAnimationEnabled()) return;
+        if (!FeatureUtilities.isTabToGtsAnimationEnabled()
+                || !mTabModelSelector.getTabModelFilterProvider()
+                            .getCurrentTabModelFilter()
+                            .isTabModelRestored()) {
+            return;
+        }
+
         assert mVisible;
         int count = 0;
         for (int i = 0; i < mModel.size(); i++) {
@@ -816,7 +822,7 @@ class TabListMediator {
     }
 
     /**
-     * @see GridTabSwitcherMediator.ResetHandler#softCleanup
+     * @see TabSwitcherMediator.ResetHandler#softCleanup
      */
     void softCleanup() {
         assert !mVisible;

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabSwitcherMediator.java

@@ -119,7 +119,7 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
     private boolean mShouldIgnoreNextSelect;
 
     private int mModelIndexWhenShown;
-    private int mTabIdwhenShown;
+    private int mTabIdWhenShown;
     private int mIndexInNewModelWhenSwitched;
     private boolean mIsSelectingInTabSwitcher;
 
@@ -225,6 +225,15 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
                     onTabSelecting(tab.getId());
                 }
             }
+
+            @Override
+            public void restoreCompleted() {
+                if (!mContainerViewModel.get(IS_VISIBLE)) return;
+
+                mResetHandler.resetWithTabList(
+                        mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter(),
+                        false, mShowTabsInMruOrder);
+            }
         };
 
         mFullscreenManager.addListener(mFullscreenListener);
@@ -335,7 +344,7 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
         Tab fromTab = TabModelUtils.getTabById(mTabModelSelector.getCurrentModel(), lastId);
         assert fromTab != null;
         if (mModelIndexWhenShown == mTabModelSelector.getCurrentModelIndex()) {
-            if (tab.getId() == mTabIdwhenShown) {
+            if (tab.getId() == mTabIdWhenShown) {
                 RecordUserAction.record("MobileTabReturnedToCurrentTab");
                 RecordHistogram.recordSparseHistogram(
                         "Tabs.TabOffsetOfSwitch." + TabSwitcherCoordinator.COMPONENT_NAME, 0);
@@ -411,7 +420,10 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
         mHandler.removeCallbacks(mSoftClearTabListRunnable);
         mHandler.removeCallbacks(mClearTabListRunnable);
         boolean quick = false;
-        if (FeatureUtilities.isTabToGtsAnimationEnabled()) {
+        if (FeatureUtilities.isTabToGtsAnimationEnabled()
+                && mTabModelSelector.getTabModelFilterProvider()
+                           .getCurrentTabModelFilter()
+                           .isTabModelRestored()) {
             quick = mResetHandler.resetWithTabList(
                     mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter(), false,
                     mShowTabsInMruOrder);
@@ -429,13 +441,17 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
 
     @Override
     public void showOverview(boolean animate) {
+        if (mTabModelSelector.getTabModelFilterProvider()
+                        .getCurrentTabModelFilter()
+                        .isTabModelRestored()) {
             mResetHandler.resetWithTabList(
                     mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter(),
                     FeatureUtilities.isTabToGtsAnimationEnabled(), mShowTabsInMruOrder);
+        }
         if (!animate) mContainerViewModel.set(ANIMATE_VISIBILITY_CHANGES, false);
         setVisibility(true);
         mModelIndexWhenShown = mTabModelSelector.getCurrentModelIndex();
-        mTabIdwhenShown = mTabModelSelector.getCurrentTabId();
+        mTabIdWhenShown = mTabModelSelector.getCurrentTabId();
         mContainerViewModel.set(ANIMATE_VISIBILITY_CHANGES, true);
         if (mIphProvider != null) {
             mIphProvider.maybeShowIPH(mTabModelSelector.isIncognitoSelected());

chrome/android/features/tab_ui/junit/src/org/chromium/chrome/browser/tasks/tab_groups/TabGroupModelFilterUnitTest.java

@@ -271,6 +271,23 @@ public class TabGroupModelFilterUnitTest {
         assertThat(mTabModel.getCount(), equalTo(6));
     }
 
+    @Test
+    // TODO(mattsimmons): This is actually testing behavior of the superclass but there's no unit
+    //  tests for the superclass today. If one ever exists, this should move to that test.
+    public void isTabModelRestored() {
+        setupTabGroupModelFilter(false, false);
+        assertThat(mTabGroupModelFilter.isTabModelRestored(), equalTo(false));
+
+        setupTabGroupModelFilter(true, false);
+        assertThat(mTabGroupModelFilter.isTabModelRestored(), equalTo(true));
+
+        setupTabGroupModelFilter(false, true);
+        assertThat(mTabGroupModelFilter.isTabModelRestored(), equalTo(true));
+
+        setupTabGroupModelFilter(true, true);
+        assertThat(mTabGroupModelFilter.isTabModelRestored(), equalTo(true));
+    }
+
     @Test
     public void addTab_ToExistingGroup() {
         Tab newTab = prepareTab(NEW_TAB_ID, NEW_TAB_ID, TAB1_ID);

chrome/android/features/tab_ui/junit/src/org/chromium/chrome/browser/tasks/tab_management/TabSwitcherMediatorUnitTest.java

@@ -433,6 +433,60 @@ public class TabSwitcherMediatorUnitTest {
         verify(mLayout).onTabSelecting(anyLong(), eq(TAB1_ID));
     }
 
+    @Test
+    public void updatesResetHandlerOnRestoreCompleted() {
+        initAndAssertAllProperties();
+        mMediator.showOverview(true);
+        assertThat(mModel.get(TabListContainerProperties.IS_VISIBLE), equalTo(true));
+
+        mTabModelObserverCaptor.getValue().restoreCompleted();
+
+        // MRU will be false unless the start surface is enabled.
+        verify(mResetHandler).resetWithTabList(mTabModelFilter, false, false);
+    }
+
+    @Test
+    public void showOverviewDoesNotUpdateResetHandlerBeforeRestoreCompleted() {
+        initAndAssertAllProperties();
+        doReturn(false).when(mTabModelFilter).isTabModelRestored();
+        mMediator.showOverview(true);
+
+        // MRU will be false unless the start surface is enabled.
+        verify(mResetHandler, never()).resetWithTabList(mTabModelFilter, true, false);
+    }
+
+    @Test
+    public void prepareOverviewDoesNotUpdateResetHandlerBeforeRestoreCompleted() {
+        initAndAssertAllProperties();
+        doReturn(false).when(mTabModelFilter).isTabModelRestored();
+        mMediator.prepareOverview();
+
+        // MRU will be false unless the start surface is enabled.
+        verify(mResetHandler, never()).resetWithTabList(mTabModelFilter, false, false);
+    }
+
+    @Test
+    public void showOverviewUpdatesResetHandlerAfterRestoreCompleted() {
+        initAndAssertAllProperties();
+        doReturn(true).when(mTabModelFilter).isTabModelRestored();
+
+        mMediator.showOverview(true);
+
+        // MRU will be false unless the start surface is enabled.
+        verify(mResetHandler).resetWithTabList(mTabModelFilter, true, false);
+    }
+
+    @Test
+    public void prepareOverviewUpdatesResetHandlerAfterRestoreCompleted() {
+        initAndAssertAllProperties();
+        doReturn(true).when(mTabModelFilter).isTabModelRestored();
+
+        mMediator.prepareOverview();
+
+        // MRU will be false unless the start surface is enabled.
+        verify(mResetHandler).resetWithTabList(mTabModelFilter, false, false);
+    }
+
     @Test
     @DisableFeatures(ChromeFeatureList.TAB_GROUPS_UI_IMPROVEMENTS_ANDROID)
     public void openDialogButton_FlagDisabled() {

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabModelFilter.java

@@ -26,6 +26,7 @@ public abstract class TabModelFilter extends EmptyTabModelObserver implements Ta
             Collections.unmodifiableList(new ArrayList<Tab>());
     private TabModel mTabModel;
     protected ObserverList<TabModelObserver> mFilteredObservers = new ObserverList<>();
+    private boolean mTabRestoreCompleted;
 
     public TabModelFilter(TabModel tabModel) {
         mTabModel = tabModel;
@@ -88,7 +89,7 @@ public abstract class TabModelFilter extends EmptyTabModelObserver implements Ta
      * @return An unmodifiable list of {@link Tab}s that are not related to any tabs
      */
     @NonNull
-    final public List<Tab> getTabsWithNoOtherRelatedTabs() {
+    public final List<Tab> getTabsWithNoOtherRelatedTabs() {
         List<Tab> tabs = new ArrayList<>();
         for (int i = 0; i < mTabModel.getCount(); i++) {
             Tab tab = mTabModel.getTabAt(i);
@@ -140,6 +141,13 @@ public abstract class TabModelFilter extends EmptyTabModelObserver implements Ta
      */
     protected abstract void resetFilterStateInternal();
 
+    /**
+     * @return Whether the tab model is fully restored.
+     */
+    public boolean isTabModelRestored() {
+        return mTabRestoreCompleted || isIncognito();
+    }
+
     /**
      * Concrete class requires to define what's the behavior when {@link TabModel} removed a
      * {@link Tab}.
@@ -264,6 +272,8 @@ public abstract class TabModelFilter extends EmptyTabModelObserver implements Ta
 
     @Override
     public void restoreCompleted() {
+        mTabRestoreCompleted = true;
+
         if (getCount() != 0) reorder();
 
         for (TabModelObserver observer : mFilteredObservers) {

chrome/android/javatests/src/org/chromium/chrome/browser/tasks/ReturnToChromeTest.java

@@ -4,11 +4,11 @@
 
 package org.chromium.chrome.browser.tasks;
 
+import static org.junit.Assert.assertEquals;
+
 import static org.chromium.chrome.browser.tasks.ReturnToChromeExperimentsUtil.TAB_SWITCHER_ON_RETURN_MS;
 
 import android.app.Activity;
-import android.content.Context;
-import android.os.SystemClock;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.filters.SmallTest;
 
@@ -22,13 +22,20 @@ import org.chromium.base.ActivityState;
 import org.chromium.base.ApplicationStatus;
 import org.chromium.base.test.util.CallbackHelper;
 import org.chromium.base.test.util.CommandLineFlags;
-import org.chromium.base.test.util.DisabledTest;
 import org.chromium.base.test.util.Feature;
+import org.chromium.base.test.util.Restriction;
 import org.chromium.chrome.browser.ChromeFeatureList;
 import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.ChromeTabbedActivity;
+import org.chromium.chrome.browser.util.FeatureUtilities;
 import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 import org.chromium.chrome.test.ChromeTabbedActivityTestRule;
+import org.chromium.chrome.test.util.MenuUtils;
+import org.chromium.content_public.browser.test.util.Criteria;
+import org.chromium.content_public.browser.test.util.CriteriaHelper;
+import org.chromium.content_public.browser.test.util.TestThreadUtils;
+import org.chromium.net.test.EmbeddedTestServer;
+import org.chromium.ui.test.util.UiRestriction;
 
 import java.util.concurrent.TimeoutException;
 
@@ -37,6 +44,7 @@ import java.util.concurrent.TimeoutException;
  * has passed.
  */
 @RunWith(ChromeJUnit4ClassRunner.class)
+@Restriction(UiRestriction.RESTRICTION_TYPE_PHONE)
 public class ReturnToChromeTest {
     @Rule
     public ChromeTabbedActivityTestRule mActivityTestRule = new ChromeTabbedActivityTestRule();
@@ -45,10 +53,12 @@ public class ReturnToChromeTest {
 
     @Before
     public void setUp() throws Exception {
-        Context context = InstrumentationRegistry.getInstrumentation().getTargetContext();
+        FeatureUtilities.setGridTabSwitcherEnabledForTesting(true);
 
         mActivityTestRule.startMainActivityFromLauncher();
         mActivity = mActivityTestRule.getActivity();
+
+        setupTabs();
     }
 
     /**
@@ -64,7 +74,7 @@ public class ReturnToChromeTest {
             "force-fieldtrial-params=FakeStudyName.Enabled:" + TAB_SWITCHER_ON_RETURN_MS
                     + "/100000"})
     public void
-    testObserverModeNotTriggeredWithoutDelay() throws Exception {
+    testTabSwitcherModeNotTriggeredWithinThreshold() throws Exception {
         finishActivityCompletely();
 
         mActivityTestRule.startMainActivityFromLauncher();
@@ -73,25 +83,51 @@ public class ReturnToChromeTest {
         Assert.assertFalse(mActivity.getLayoutManager().overviewVisible());
     }
 
+    /**
+     * Test that overview mode is triggered if the delay is shorter than the interval between
+     * stop and start.
+     */
     @Test
     @SmallTest
     @Feature({"ReturnToChrome"})
-    @DisabledTest(message = "crbug.com/955436")
     @CommandLineFlags.Add({ChromeSwitches.DISABLE_FIRST_RUN_EXPERIENCE,
             "enable-features=" + ChromeFeatureList.TAB_SWITCHER_ON_RETURN + "<FakeStudyName",
             "force-fieldtrials=FakeStudyName/Enabled",
-            "force-fieldtrial-params=FakeStudyName.Enabled:" + TAB_SWITCHER_ON_RETURN_MS + "/1"})
+            "force-fieldtrial-params=FakeStudyName.Enabled:" + TAB_SWITCHER_ON_RETURN_MS + "/0"})
     public void
-    testObserverModeTriggeredWithDelay() throws Exception {
+    testTabSwitcherModeTriggeredBeyondThreshold() throws Exception {
         finishActivityCompletely();
 
-        // Sleep past the timeout.
-        SystemClock.sleep(30);
-
         mActivityTestRule.startMainActivityFromLauncher();
         mActivity = mActivityTestRule.getActivity();
 
         Assert.assertTrue(mActivity.getLayoutManager().overviewVisible());
+
+        CriteriaHelper.pollUiThread(Criteria.equals(true,
+                mActivityTestRule.getActivity()
+                        .getTabModelSelector()
+                        .getTabModelFilterProvider()
+                        .getCurrentTabModelFilter()::isTabModelRestored));
+
+        assertEquals(2, mActivityTestRule.getActivity().getTabModelSelector().getTotalTabCount());
+    }
+
+    private void setupTabs() throws InterruptedException {
+        TestThreadUtils.runOnUiThreadBlocking(
+                () -> mActivityTestRule.getActivity().getTabModelSelector().closeAllTabs());
+        EmbeddedTestServer testServer =
+                EmbeddedTestServer.createAndStartServer(InstrumentationRegistry.getContext());
+        final String url = testServer.getURL("/chrome/test/data/android/navigate/simple.html");
+
+        // Add 2 tabs.
+        MenuUtils.invokeCustomMenuActionSync(InstrumentationRegistry.getInstrumentation(),
+                mActivity, org.chromium.chrome.R.id.new_tab_menu_id);
+        mActivityTestRule.loadUrl(url);
+        MenuUtils.invokeCustomMenuActionSync(InstrumentationRegistry.getInstrumentation(),
+                mActivity, org.chromium.chrome.R.id.new_tab_menu_id);
+        mActivityTestRule.loadUrl(url);
+
+        assertEquals(2, mActivity.getTabModelSelector().getTotalTabCount());
     }
 
     private void finishActivityCompletely() throws InterruptedException, TimeoutException {