Simplify ReturnToChromeTest by reusing test helpers

Simplify ReturnToChromeTest before adding more tests to it in
http://crrev.com/c/1903526.

Bug: 1022289
Change-Id: I5faa1814addfa58f3cb5729b7176025ae3092fc2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1904958
Commit-Queue: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714020}

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

@@ -8,7 +8,6 @@ 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.support.test.InstrumentationRegistry;
 import android.support.test.filters.SmallTest;
 
@@ -18,47 +17,47 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-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.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.flags.FeatureUtilities;
+import org.chromium.chrome.browser.tasks.tab_management.TabUiTestHelper;
 import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 import org.chromium.chrome.test.ChromeTabbedActivityTestRule;
-import org.chromium.chrome.test.util.MenuUtils;
+import org.chromium.chrome.test.util.ApplicationTestUtils;
 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;
-
 /**
  * Tests the functionality of return to chrome features that open overview mode if the timeout
  * has passed.
  */
 @RunWith(ChromeJUnit4ClassRunner.class)
 @Restriction(UiRestriction.RESTRICTION_TYPE_PHONE)
+@CommandLineFlags.Add({ChromeSwitches.DISABLE_FIRST_RUN_EXPERIENCE,
+        "enable-features=" + ChromeFeatureList.TAB_SWITCHER_ON_RETURN + "<Study",
+        "force-fieldtrials=Study/Group"})
 public class ReturnToChromeTest {
+    private static final String BASE_PARAMS =
+            "force-fieldtrial-params=Study.Group:" + TAB_SWITCHER_ON_RETURN_MS + "/0";
     @Rule
     public ChromeTabbedActivityTestRule mActivityTestRule = new ChromeTabbedActivityTestRule();
 
-    private ChromeTabbedActivity mActivity;
+    private String mUrl;
 
     @Before
     public void setUp() {
         FeatureUtilities.setGridTabSwitcherEnabledForTesting(true);
 
-        mActivityTestRule.startMainActivityOnBlankPage();
-        mActivity = mActivityTestRule.getActivity();
+        EmbeddedTestServer testServer =
+                EmbeddedTestServer.createAndStartServer(InstrumentationRegistry.getContext());
+        mUrl = testServer.getURL("/chrome/test/data/android/navigate/simple.html");
 
-        setupTabs();
+        mActivityTestRule.startMainActivityOnBlankPage();
     }
 
     /**
@@ -68,19 +67,14 @@ public class ReturnToChromeTest {
     @Test
     @SmallTest
     @Feature({"ReturnToChrome"})
-    @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
-                    + "/100000"})
-    public void
-    testTabSwitcherModeNotTriggeredWithinThreshold() throws Exception {
-        finishActivityCompletely();
+    @CommandLineFlags.Add({BASE_PARAMS + "/" + TAB_SWITCHER_ON_RETURN_MS + "/100000"})
+    public void testTabSwitcherModeNotTriggeredWithinThreshold() throws Exception {
+        TabUiTestHelper.prepareTabsWithThumbnail(mActivityTestRule, 2, 0, mUrl);
+        ApplicationTestUtils.finishActivity(mActivityTestRule.getActivity());
 
         mActivityTestRule.startMainActivityFromLauncher();
-        mActivity = mActivityTestRule.getActivity();
 
-        Assert.assertFalse(mActivity.getLayoutManager().overviewVisible());
+        Assert.assertFalse(mActivityTestRule.getActivity().getLayoutManager().overviewVisible());
     }
 
     /**
@@ -90,18 +84,14 @@ public class ReturnToChromeTest {
     @Test
     @SmallTest
     @Feature({"ReturnToChrome"})
-    @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 + "/0"})
-    public void
-    testTabSwitcherModeTriggeredBeyondThreshold() throws Exception {
-        finishActivityCompletely();
+    @CommandLineFlags.Add({BASE_PARAMS + "/" + TAB_SWITCHER_ON_RETURN_MS + "/0"})
+    public void testTabSwitcherModeTriggeredBeyondThreshold() throws Exception {
+        TabUiTestHelper.prepareTabsWithThumbnail(mActivityTestRule, 2, 0, mUrl);
+        ApplicationTestUtils.finishActivity(mActivityTestRule.getActivity());
 
         mActivityTestRule.startMainActivityFromLauncher();
-        mActivity = mActivityTestRule.getActivity();
 
-        Assert.assertTrue(mActivity.getLayoutManager().overviewVisible());
+        Assert.assertTrue(mActivityTestRule.getActivity().getLayoutManager().overviewVisible());
 
         CriteriaHelper.pollUiThread(Criteria.equals(true,
                 mActivityTestRule.getActivity()
@@ -111,45 +101,4 @@ public class ReturnToChromeTest {
 
         assertEquals(2, mActivityTestRule.getActivity().getTabModelSelector().getTotalTabCount());
     }
-
-    private void setupTabs() {
-        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 TimeoutException {
-        final CallbackHelper activityCallback = new CallbackHelper();
-        ApplicationStatus.ActivityStateListener stateListener =
-                new ApplicationStatus.ActivityStateListener() {
-                    @Override
-                    public void onActivityStateChange(Activity activity, int newState) {
-                        if (newState == ActivityState.STOPPED) {
-                            activityCallback.notifyCalled();
-                            ApplicationStatus.unregisterActivityStateListener(this);
-                        }
-                    }
-                };
-
-        ApplicationStatus.registerStateListenerForAllActivities(stateListener);
-        try {
-            mActivity.finish();
-            activityCallback.waitForCallback("Activity did not stop as expected", 0);
-            mActivityTestRule.setActivity(null);
-        } finally {
-            ApplicationStatus.unregisterActivityStateListener(stateListener);
-        }
-    }
 }