Modularize TabWindowManager to chrome/browser/tabmodel

Split TabWindowManagerImpl out of interface, then move the interface,
the impl and the factory to the tabmodel module.

Narrow down the interface to be a bit smaller and more generic.

Bug: 1112922
Change-Id: I1c76e4ad86fae7435e31211ae857a8d772366b80
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2461950Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817080}

chrome/android/BUILD.gn

@@ -1048,6 +1048,7 @@ android_library("chrome_test_java") {
     "//chrome/browser/share/android:java_resources",
     "//chrome/browser/tab:java",
     "//chrome/browser/tabmodel:java",
+    "//chrome/browser/tabmodel/internal:java",
     "//chrome/browser/tabpersistence:java",
     "//chrome/browser/thumbnail:java",
     "//chrome/browser/thumbnail:javatests",

chrome/android/chrome_java_sources.gni

@@ -1536,7 +1536,6 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/tabmodel/TabPersistencePolicy.java",
   "java/src/org/chromium/chrome/browser/tabmodel/TabPersistentStore.java",
   "java/src/org/chromium/chrome/browser/tabmodel/TabPersister.java",
-  "java/src/org/chromium/chrome/browser/tabmodel/TabWindowManager.java",
   "java/src/org/chromium/chrome/browser/tabmodel/TabbedModeTabPersistencePolicy.java",
   "java/src/org/chromium/chrome/browser/tabmodel/document/TabDelegate.java",
   "java/src/org/chromium/chrome/browser/tasks/ConditionalTabStripUtils.java",

chrome/android/java/src/org/chromium/chrome/browser/app/tabmodel/TabWindowManagerSingleton.java

@@ -4,14 +4,19 @@
 
 package org.chromium.chrome.browser.app.tabmodel;
 
+import androidx.annotation.VisibleForTesting;
+
 import org.chromium.base.ThreadUtils;
+import org.chromium.chrome.browser.tabmodel.TabModelSelectorFactory;
 import org.chromium.chrome.browser.tabmodel.TabWindowManager;
+import org.chromium.chrome.browser.tabmodel.TabWindowManagerFactory;
 
 /**
  * Glue-level singleton instance of {@link TabWindowManager}.
  */
 public class TabWindowManagerSingleton {
     private static TabWindowManager sInstance;
+    private static TabModelSelectorFactory sSelectorFactoryForTesting;
 
     /**
      * @return The singleton instance of {@link TabWindowManager}.
@@ -19,9 +24,23 @@ public class TabWindowManagerSingleton {
     public static TabWindowManager getInstance() {
         ThreadUtils.assertOnUiThread();
         if (sInstance == null) {
-            sInstance = new TabWindowManager(new DefaultTabModelSelectorFactory(),
-                    AsyncTabParamsManagerSingleton.getInstance());
+            TabModelSelectorFactory selectorFactory = sSelectorFactoryForTesting == null
+                    ? new DefaultTabModelSelectorFactory()
+                    : sSelectorFactoryForTesting;
+            sInstance = TabWindowManagerFactory.createInstance(
+                    selectorFactory, AsyncTabParamsManagerSingleton.getInstance());
         }
         return sInstance;
     }
+
+    /**
+     * Allows overriding the default {@link TabModelSelectorFactory} with another one.  Typically
+     * for testing.
+     * @param factory A {@link TabModelSelectorFactory} instance.
+     */
+    @VisibleForTesting
+    public static void setTabModelSelectorFactoryForTesting(TabModelSelectorFactory factory) {
+        assert sInstance == null;
+        sSelectorFactoryForTesting = factory;
+    }
 }
\ No newline at end of file

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

@@ -398,7 +398,7 @@ public class TabbedModeTabPersistencePolicy implements TabPersistencePolicy {
         }
 
         private boolean shouldDeleteTabFile(int tabId, TabWindowManager tabWindowManager) {
-            return !tabWindowManager.tabExistsInAnySelector(tabId) && !mOtherTabIds.get(tabId);
+            return tabWindowManager.getTabById(tabId) == null && !mOtherTabIds.get(tabId);
         }
 
         /**

chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/ContextMenuLoadUrlParamsTest.java

@@ -80,18 +80,16 @@ public class ContextMenuLoadUrlParamsTest {
         // Plant RecordingTabModelSelector as the TabModelSelector used in Main. The factory has to
         // be set before super.setUp(), as super.setUp() creates Main and consequently the
         // TabModelSelector.
-        TestThreadUtils.runOnUiThreadBlocking(() -> {
-            TabWindowManagerSingleton.getInstance().setTabModelSelectorFactory(
-                    new TabModelSelectorFactory() {
-                        @Override
-                        public TabModelSelector buildSelector(Activity activity,
-                                TabCreatorManager tabCreatorManager,
-                                NextTabPolicySupplier nextTabPolicySupplier, int selectorIndex) {
-                            return new RecordingTabModelSelector(activity, tabCreatorManager,
-                                    new ChromeTabModelFilterFactory(), selectorIndex);
-                        }
-                    });
-        });
+        TabWindowManagerSingleton.setTabModelSelectorFactoryForTesting(
+                new TabModelSelectorFactory() {
+                    @Override
+                    public TabModelSelector buildSelector(Activity activity,
+                            TabCreatorManager tabCreatorManager,
+                            NextTabPolicySupplier nextTabPolicySupplier, int selectorIndex) {
+                        return new RecordingTabModelSelector(activity, tabCreatorManager,
+                                new ChromeTabModelFilterFactory(), selectorIndex);
+                    }
+                });
         mActivityTestRule.startMainActivityOnBlankPage();
         TestThreadUtils.runOnUiThreadBlocking(
                 () -> { FirstRunStatus.setFirstRunFlowComplete(true); });

chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/TabPersistentStoreTest.java

@@ -219,10 +219,15 @@ public class TabPersistentStoreTest {
     private TestTabModelDirectory mMockDirectory;
     private AdvancedMockContext mAppContext;
     private SharedPreferencesManager mPreferences;
+    private TabWindowManagerImpl mTabWindowManager;
 
     @Before
     public void setUp() {
         TestThreadUtils.runOnUiThreadBlocking(() -> {
+            TabWindowManagerSingleton.setTabModelSelectorFactoryForTesting(
+                    mMockTabModelSelectorFactory);
+            mTabWindowManager = (TabWindowManagerImpl) TabWindowManagerSingleton.getInstance();
+
             mChromeActivity = new ChromeActivity() {
                 @Override
                 protected boolean handleBackPressed() {
@@ -266,8 +271,7 @@ public class TabPersistentStoreTest {
     @After
     public void tearDown() {
         TestThreadUtils.runOnUiThreadBlocking(() -> {
-            TabWindowManagerSingleton.getInstance().onActivityStateChange(
-                    mChromeActivity, ActivityState.DESTROYED);
+            mTabWindowManager.onActivityStateChange(mChromeActivity, ActivityState.DESTROYED);
         });
         mMockDirectory.tearDown();
     }
@@ -697,13 +701,11 @@ public class TabPersistentStoreTest {
                 TestThreadUtils.runOnUiThreadBlocking(new Callable<TestTabModelSelector>() {
                     @Override
                     public TestTabModelSelector call() {
-                        TabWindowManager tabWindowManager = TabWindowManagerSingleton.getInstance();
-                        tabWindowManager.setTabModelSelectorFactory(mMockTabModelSelectorFactory);
                         // Clear any existing TestTabModelSelector (required when
                         // createAndRestoreRealTabModelImpls is called multiple times in one test).
-                        tabWindowManager.onActivityStateChange(
+                        mTabWindowManager.onActivityStateChange(
                                 mChromeActivity, ActivityState.DESTROYED);
-                        return (TestTabModelSelector) tabWindowManager.requestSelector(
+                        return (TestTabModelSelector) mTabWindowManager.requestSelector(
                                 mChromeActivity, mChromeActivity, null, 0);
                     }
                 });

chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/TabWindowManagerTest.java

@@ -10,6 +10,7 @@ import androidx.test.filters.SmallTest;
 
 import org.junit.After;
 import org.junit.Assert;
+import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -32,8 +33,10 @@ import java.util.ArrayList;
 import java.util.List;
 
 /**
- * Test for {@link TabWindowManager} APIs.  Makes sure the class handles multiple {@link Activity}s
- * requesting {@link TabModelSelector}s, {@link Activity}s getting destroyed, etc..
+ * Test for {@link TabWindowManagerImpl} through {@link TabWindowManagerSingleton}.
+ *
+ * Makes sure the class handles multiple {@link Activity}s requesting {@link TabModelSelector}s,
+ * {@link Activity}s getting destroyed, etc.
  */
 @RunWith(ChromeJUnit4ClassRunner.class)
 public class TabWindowManagerTest {
@@ -48,6 +51,12 @@ public class TabWindowManagerTest {
                 }
             };
 
+    @Before
+    public void setUp() {
+        TabWindowManagerSingleton.setTabModelSelectorFactoryForTesting(
+                mMockTabModelSelectorFactory);
+    }
+
     private ChromeActivity buildActivity() {
         ChromeActivity activity = new CustomTabActivity();
         mActivities.add(activity);
@@ -62,7 +71,6 @@ public class TabWindowManagerTest {
 
     private MockTabModelSelector requestSelector(ChromeActivity activity, int requestedIndex) {
         final TabWindowManager manager = TabWindowManagerSingleton.getInstance();
-        manager.setTabModelSelectorFactory(mMockTabModelSelectorFactory);
         return (MockTabModelSelector) manager.requestSelector(
                 activity, activity, () -> NextTabPolicy.HIERARCHICAL, requestedIndex);
     }
@@ -186,7 +194,8 @@ public class TabWindowManagerTest {
     }
 
     /**
-     * Test that a destroyed {@link Activity} properly gets removed from {@link TabWindowManager}.
+     * Test that a destroyed {@link Activity} properly gets removed from {@link
+     * TabWindowManagerImpl}.
      */
     @Test
     @SmallTest
@@ -290,20 +299,20 @@ public class TabWindowManagerTest {
         Tab tab1 = selector0.addMockTab();
         Tab tab2 = selector1.addMockIncognitoTab();
 
-        Assert.assertFalse(manager.tabExistsInAnySelector(tab1.getId() - 1));
-        Assert.assertTrue(manager.tabExistsInAnySelector(tab1.getId()));
-        Assert.assertTrue(manager.tabExistsInAnySelector(tab2.getId()));
-        Assert.assertFalse(manager.tabExistsInAnySelector(tab2.getId() + 1));
+        Assert.assertNull(manager.getTabById(tab1.getId() - 1));
+        Assert.assertNotNull(manager.getTabById(tab1.getId()));
+        Assert.assertNotNull(manager.getTabById(tab2.getId()));
+        Assert.assertNull(manager.getTabById(tab2.getId() + 1));
 
         AsyncTabParamsManager asyncTabParamsManager = AsyncTabParamsManagerSingleton.getInstance();
         asyncTabParamsManager.getAsyncTabParams().clear();
         final int asyncTabId = 123;
         final TabReparentingParams dummyParams =
                 new TabReparentingParams(new MockTab(0, false), null);
-        Assert.assertFalse(manager.tabExistsInAnySelector(asyncTabId));
+        Assert.assertNull(manager.getTabById(asyncTabId));
         asyncTabParamsManager.add(asyncTabId, dummyParams);
         try {
-            Assert.assertTrue(manager.tabExistsInAnySelector(asyncTabId));
+            Assert.assertNotNull(manager.getTabById(asyncTabId));
         } finally {
             asyncTabParamsManager.getAsyncTabParams().clear();
         }

chrome/browser/tabmodel/BUILD.gn

@@ -35,6 +35,7 @@ android_library("java") {
     "android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorTabObserver.java",
     "android/java/src/org/chromium/chrome/browser/tabmodel/TabModelUtils.java",
     "android/java/src/org/chromium/chrome/browser/tabmodel/TabReparentingParams.java",
+    "android/java/src/org/chromium/chrome/browser/tabmodel/TabWindowManager.java",
   ]
   deps = [
     "//base:base_java",
@@ -49,5 +50,8 @@ android_library("java") {
 android_library_factory("factory_java") {
   deps = [ ":java" ]
 
-  sources = [ "internal/android/java/src/org/chromium/chrome/browser/tabmodel/AsyncTabParamsManagerFactory.java" ]
+  sources = [
+    "internal/android/java/src/org/chromium/chrome/browser/tabmodel/AsyncTabParamsManagerFactory.java",
+    "internal/android/java/src/org/chromium/chrome/browser/tabmodel/TabWindowManagerFactory.java",
+  ]
 }

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

+// Copyright 2020 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.
+
+package org.chromium.chrome.browser.tabmodel;
+
+import android.app.Activity;
+
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.tabmodel.NextTabPolicy.NextTabPolicySupplier;
+import org.chromium.ui.base.WindowAndroid;
+
+/**
+ * Manages multiple {@link TabModelSelector} instances, each owned by different {@link Activity}s.
+ *
+ * Each of the 0-3 {@link WindowAndroid} contains 1 {@link Activity},
+ * which contains 1 {@link TabModelSelector}, which contains 2 {@link TabModel}s,
+ * each of which contains n {@link Tab}s.
+ *
+ * Also manages tabs being reparented in AsyncTabParamsManager.
+ *
+ * This is the highest level of the hierarchy of Tab containers.
+ */
+public interface TabWindowManager {
+    /** The maximum number of simultaneous TabModelSelector instances in this Application. */
+    int MAX_SIMULTANEOUS_SELECTORS = 3;
+
+    /**
+     * Called to request a {@link TabModelSelector} based on {@code index}. Note that the
+     * {@link TabModelSelector} returned might not actually be the one related to {@code index} and
+     * {@link #getIndexForWindow(Activity)} should be called to grab the actual index if required.
+     *
+     * @param tabCreatorManager An instance of {@link TabCreatorManager}.
+     * @param nextTabPolicySupplier An instance of {@link NextTabPolicySupplier}.
+     * @param index The index of the requested {@link TabModelSelector}. Not guaranteed to be the
+     *              index of the {@link TabModelSelector} returned.
+     * @return A {@link TabModelSelector} index, or {@code null} if there are too many
+     *         {@link TabModelSelector}s already built.
+     */
+    TabModelSelector requestSelector(Activity activity, TabCreatorManager tabCreatorManager,
+            NextTabPolicySupplier nextTabPolicySupplier, int index);
+
+    /**
+     * An index that represents the invalid state (i.e. when the window wasn't found in the list).
+     */
+    int INVALID_WINDOW_INDEX = -1;
+
+    /**
+     * Finds the current index of the {@link TabModelSelector} bound to {@code window}.
+     * @param activity The {@link Activity} to find the index of the {@link TabModelSelector}
+     *                 for.  This uses the underlying {@link Activity} stored in the
+     *                 {@link WindowAndroid}.
+     * @return         The index of the {@link TabModelSelector} or {@link #INVALID_WINDOW_INDEX} if
+     *                 not found.
+     */
+    int getIndexForWindow(Activity activity);
+
+    /**
+     * @return The number of {@link TabModelSelector}s currently assigned to {@link Activity}s.
+     */
+    int getNumberOfAssignedTabModelSelectors();
+
+    /**
+     * @return The total number of incognito tabs across all tab model selectors.
+     */
+    int getIncognitoTabCount();
+
+    /**
+     * @param tab The tab to look for in each model.
+     * @return The TabModel containing the given Tab or null if one doesn't exist.
+     **/
+    TabModel getTabModelForTab(Tab tab);
+
+    /**
+     * @param tabId The ID of the tab in question.
+     * @return Specified {@link Tab} or {@code null} if the {@link Tab} is not found.
+     */
+    Tab getTabById(int tabId);
+}

chrome/browser/tabmodel/internal/BUILD.gn

@@ -8,10 +8,13 @@ android_library("java") {
   visibility = [
     "//chrome/android:chrome_all_java",
     "//chrome/android:chrome_junit_tests__java_binary",
+    "//chrome/android:chrome_test_java",
   ]
   sources = [
     "android/java/src/org/chromium/chrome/browser/tabmodel/AsyncTabParamsManagerFactory.java",
     "android/java/src/org/chromium/chrome/browser/tabmodel/AsyncTabParamsManagerImpl.java",
+    "android/java/src/org/chromium/chrome/browser/tabmodel/TabWindowManagerFactory.java",
+    "android/java/src/org/chromium/chrome/browser/tabmodel/TabWindowManagerImpl.java",
   ]
   deps = [
     "//base:base_java",

chrome/browser/tabmodel/internal/android/java/src/org/chromium/chrome/browser/tabmodel/TabWindowManagerFactory.java

+// Copyright 2020 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.
+
+package org.chromium.chrome.browser.tabmodel;
+
+/**
+ * Factory for creating {@link TabWindowManager}.
+ */
+public class TabWindowManagerFactory {
+    /**
+     * @return New instance of {@link TabWindowManagerImpl}.
+     */
+    public static TabWindowManager createInstance(
+            TabModelSelectorFactory selectorFactory, AsyncTabParamsManager asyncTabParamsManager) {
+        return new TabWindowManagerImpl(selectorFactory, asyncTabParamsManager);
+    }
+}

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabWindowManager.java → chrome/browser/tabmodel/internal/android/java/src/org/chromium/chrome/browser/tabmodel/TabWindowManagerImpl.java

@@ -7,14 +7,11 @@ package org.chromium.chrome.browser.tabmodel;
 import android.app.Activity;
 import android.util.SparseArray;
 
-import androidx.annotation.VisibleForTesting;
-
 import org.chromium.base.ActivityState;
 import org.chromium.base.ApplicationStatus;
 import org.chromium.base.ApplicationStatus.ActivityStateListener;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tabmodel.NextTabPolicy.NextTabPolicySupplier;
-import org.chromium.ui.base.WindowAndroid;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -23,16 +20,10 @@ import java.util.Map;
 
 /**
  * Manages multiple {@link TabModelSelector} instances, each owned by different {@link Activity}s.
+ *
+ * Also manages tabs being reparented in AsyncTabParamsManager.
  */
-public class TabWindowManager implements ActivityStateListener {
-    /**
-     * An index that represents the invalid state (i.e. when the window wasn't found in the list).
-     */
-    public static final int INVALID_WINDOW_INDEX = -1;
-
-    /** The maximum number of simultaneous TabModelSelector instances in this Application. */
-    public static final int MAX_SIMULTANEOUS_SELECTORS = 3;
-
+public class TabWindowManagerImpl implements ActivityStateListener, TabWindowManager {
     private TabModelSelectorFactory mSelectorFactory;
     private final AsyncTabParamsManager mAsyncTabParamsManager;
 
@@ -40,18 +31,18 @@ public class TabWindowManager implements ActivityStateListener {
 
     private Map<Activity, TabModelSelector> mAssignments = new HashMap<>();
 
-    /**
-     * Called to request a {@link TabModelSelector} based on {@code index}. Note that the
-     * {@link TabModelSelector} returned might not actually be the one related to {@code index} and
-     * {@link #getIndexForWindow(Activity)} should be called to grab the actual index if required.
-     *
-     * @param tabCreatorManager An instance of {@link TabCreatorManager}.
-     * @param nextTabPolicySupplier An instance of {@link NextTabPolicySupplier}.
-     * @param index The index of the requested {@link TabModelSelector}. Not guaranteed to be the
-     *              index of the {@link TabModelSelector} returned.
-     * @return A {@link TabModelSelector} index, or {@code null} if there are too many
-     *         {@link TabModelSelector}s already built.
-     */
+    TabWindowManagerImpl(
+            TabModelSelectorFactory selectorFactory, AsyncTabParamsManager asyncTabParamsManager) {
+        mSelectorFactory = selectorFactory;
+        mAsyncTabParamsManager = asyncTabParamsManager;
+        ApplicationStatus.registerStateListenerForAllActivities(this);
+
+        for (int i = 0; i < TabWindowManager.MAX_SIMULTANEOUS_SELECTORS; i++) {
+            mSelectors.add(null);
+        }
+    }
+
+    @Override
     public TabModelSelector requestSelector(Activity activity, TabCreatorManager tabCreatorManager,
             NextTabPolicySupplier nextTabPolicySupplier, int index) {
         if (mAssignments.get(activity) != null) {
@@ -80,32 +71,21 @@ public class TabWindowManager implements ActivityStateListener {
         return selector;
     }
 
-    /**
-     * Finds the current index of the {@link TabModelSelector} bound to {@code window}.
-     * @param activity The {@link Activity} to find the index of the {@link TabModelSelector}
-     *                 for.  This uses the underlying {@link Activity} stored in the
-     *                 {@link WindowAndroid}.
-     * @return         The index of the {@link TabModelSelector} or {@link #INVALID_WINDOW_INDEX} if
-     *                 not found.
-     */
+    @Override
     public int getIndexForWindow(Activity activity) {
-        if (activity == null) return INVALID_WINDOW_INDEX;
+        if (activity == null) return TabWindowManager.INVALID_WINDOW_INDEX;
         TabModelSelector selector = mAssignments.get(activity);
-        if (selector == null) return INVALID_WINDOW_INDEX;
+        if (selector == null) return TabWindowManager.INVALID_WINDOW_INDEX;
         int index = mSelectors.indexOf(selector);
-        return index == -1 ? INVALID_WINDOW_INDEX : index;
+        return index == -1 ? TabWindowManager.INVALID_WINDOW_INDEX : index;
     }
 
-    /**
-     * @return The number of {@link TabModelSelector}s currently assigned to {@link Activity}s.
-     */
+    @Override
     public int getNumberOfAssignedTabModelSelectors() {
         return mAssignments.size();
     }
 
-    /**
-     * @return The total number of incognito tabs across all tab model selectors.
-     */
+    @Override
     public int getIncognitoTabCount() {
         int count = 0;
         for (int i = 0; i < mSelectors.size(); i++) {
@@ -124,18 +104,7 @@ public class TabWindowManager implements ActivityStateListener {
         return count;
     }
 
-    /**
-     * @param tabId The ID of the tab in question.
-     * @return Whether the given tab exists in any currently loaded selector.
-     */
-    public boolean tabExistsInAnySelector(int tabId) {
-        return getTabById(tabId) != null;
-    }
-
-    /**
-     * @param tab The tab to look for in each model.
-     * @return The TabModel containing the given Tab or null if one doesn't exist.
-     **/
+    @Override
     public TabModel getTabModelForTab(Tab tab) {
         if (tab == null) return null;
 
@@ -150,10 +119,7 @@ public class TabWindowManager implements ActivityStateListener {
         return null;
     }
 
-    /**
-     * @param tabId The ID of the tab in question.
-     * @return Specified {@link Tab} or {@code null} if the {@link Tab} is not found.
-     */
+    @Override
     public Tab getTabById(int tabId) {
         for (int i = 0; i < mSelectors.size(); i++) {
             TabModelSelector selector = mSelectors.get(i);
@@ -170,31 +136,15 @@ public class TabWindowManager implements ActivityStateListener {
         return null;
     }
 
+    // ActivityStateListener
     @Override
     public void onActivityStateChange(Activity activity, int newState) {
         if (newState == ActivityState.DESTROYED && mAssignments.containsKey(activity)) {
             int index = mSelectors.indexOf(mAssignments.remove(activity));
-            if (index >= 0) mSelectors.set(index, null);
+            if (index >= 0) {
+                mSelectors.set(index, null);
+            }
             // TODO(dtrainor): Move TabModelSelector#destroy() calls here.
         }
     }
-
-    /**
-     * Allows overriding the default {@link TabModelSelectorFactory} with another one.  Typically
-     * for testing.
-     * @param factory A {@link TabModelSelectorFactory} instance.
-     */
-    @VisibleForTesting
-    public void setTabModelSelectorFactory(TabModelSelectorFactory factory) {
-        mSelectorFactory = factory;
-    }
-
-    public TabWindowManager(
-            TabModelSelectorFactory selectorFactory, AsyncTabParamsManager asyncTabParamsManager) {
-        mSelectorFactory = selectorFactory;
-        mAsyncTabParamsManager = asyncTabParamsManager;
-        ApplicationStatus.registerStateListenerForAllActivities(this);
-
-        for (int i = 0; i < MAX_SIMULTANEOUS_SELECTORS; i++) mSelectors.add(null);
-    }
 }