Reland "Render Tabs into Bottom sheet"

This reverts commit 58e3dc5d.

Reason for revert: The failed CrOS test doesn't seem affected
by the newly introduced Android code. 

Original change's description:
> Revert "Render Tabs into Bottom sheet"
> 
> This reverts commit a4ae2e1f.
> 
> Reason for revert:
> All/AutofillInteractiveIsolationTest.SimpleCrossSiteFill/1 started
> to fail on ChromeOS likely after this change.
> https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/linux-chromeos-rel/8133
> https://ci.chromium.org/buildbot/chromium.chromiumos/linux-chromeos-dbg/5701
> 
> Original change's description:
> > Render Tabs into Bottom sheet
> > 
> > This CL shapes the role of a KeyboardAccessoryData.Tab element:
> > It is an element that provides a specific benefit to the Manual UI by...
> > ... providing data that is used by the bar to render a tab (upcoming)
> > ... providing the content for a separate tab in the bottom sheet.
> > 
> > This means, that the bottom sheet provides space for tabs and manages the
> > general visibility and active states of tabs.
> > The exact content of a tab doesn't matter to the AccessorySheetComponent.
> > That way, it should become fairly straight forward to implement a new tab
> > that is rendered into bottom sheet and accessory.
> > 
> > The first concrete instance of a bottom sheet will follow soon: a
> > bottom sheet that contains password related actions and data.
> > (It's important to not mix this specific data into the AccessorySheet
> > component as other upcoming sheets are already planned, like one for
> > payments and one for address data.)
> > 
> > Bug: 811747
> > Change-Id: Id8bd8c389496246166d26a6c298056a142c36566
> > Reviewed-on: https://chromium-review.googlesource.com/1047285
> > Commit-Queue: Friedrich Horschig <fhorschig@chromium.org>
> > Reviewed-by: Bernhard Bauer <bauerb@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#559180}
> 
> TBR=bauerb@chromium.org,fhorschig@chromium.org
> 
> Change-Id: I879e4e89c674d47562c662b5c2bbac3487546062
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 811747
> Reviewed-on: https://chromium-review.googlesource.com/1063732
> Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
> Commit-Queue: Kinuko Yasuda <kinuko@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#559463}

TBR=kinuko@chromium.org,bauerb@chromium.org,fhorschig@chromium.org

Change-Id: I17ef937cfed19aa4b3fe9b10220b77ac349ffb31
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 811747
Reviewed-on: https://chromium-review.googlesource.com/1063790Reviewed-by: Friedrich Horschig <fhorschig@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Friedrich Horschig <fhorschig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559469}

chrome/android/java/res/layout/empty_accessory_sheet.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2018 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. -->
+
+<!-- This Layout is mainly used in tests. Therefore use possible UnusedResource warnings. -->
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    tools:ignore="UnusedResources"
+    android:orientation="vertical"
+    android:layout_height="match_parent"
+    android:layout_width="match_parent"/>

chrome/android/java/res/layout/keyboard_accessory_sheet.xml

@@ -3,14 +3,11 @@
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file. -->
 
-<LinearLayout
+<android.support.v4.view.ViewPager
     xmlns:android="http://schemas.android.com/apk/res/android"
-    android:id="@+id/keyboard_accessory"
     android:background="@drawable/keyboard_accessory_background"
-    android:contentDescription="@string/autofill_keyboard_accessory_content_description"
     android:fillViewport="true"
     android:layout_gravity="start|bottom"
     android:layout_height="@dimen/keyboard_accessory_sheet_height"
     android:layout_width="match_parent"
-    android:orientation="vertical"
     android:visibility="gone"/>
\ No newline at end of file

chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java

@@ -59,6 +59,7 @@ import org.chromium.chrome.browser.appmenu.AppMenuHandler;
 import org.chromium.chrome.browser.appmenu.AppMenuObserver;
 import org.chromium.chrome.browser.appmenu.AppMenuPropertiesDelegate;
 import org.chromium.chrome.browser.autofill.keyboard_accessory.KeyboardAccessoryCoordinator;
+import org.chromium.chrome.browser.autofill.keyboard_accessory.ManualFillingCoordinator;
 import org.chromium.chrome.browser.bookmarks.BookmarkModel;
 import org.chromium.chrome.browser.bookmarks.BookmarkUtils;
 import org.chromium.chrome.browser.compositor.CompositorViewHolder;
@@ -266,7 +267,7 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
     private BottomSheet mBottomSheet;
     private ContextualSuggestionsCoordinator mContextualSuggestionsCoordinator;
     private FadingBackgroundView mFadingBackgroundView;
-    private KeyboardAccessoryCoordinator mKeyboardAccessoryCoordinator;
+    private ManualFillingCoordinator mManualFillingController;
 
     // Time in ms that it took took us to inflate the initial layout
     private long mInflateInitialLayoutDurationMs;
@@ -391,8 +392,9 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
         // SurfaceView's 'hole' clipping during animations that are notified to the window.
         getWindowAndroid().setAnimationPlaceholderView(mCompositorViewHolder.getCompositorView());
 
-        mKeyboardAccessoryCoordinator = new KeyboardAccessoryCoordinator(
-                getWindowAndroid(), findViewById(R.id.keyboard_accessory_stub));
+        mManualFillingController = new ManualFillingCoordinator(getWindowAndroid(),
+                findViewById(R.id.keyboard_accessory_stub),
+                findViewById(R.id.keyboard_accessory_sheet_stub));
 
         initializeToolbar();
         initializeTabModels();
@@ -676,7 +678,7 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
      * @return The {@link KeyboardAccessoryCoordinator} that belongs to this activity.
      */
     public KeyboardAccessoryCoordinator getKeyboardAccessory() {
-        return mKeyboardAccessoryCoordinator;
+        return mManualFillingController.getKeyboardAccessory();
     }
 
     /**
@@ -1223,9 +1225,9 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
             mTabContentManager = null;
         }
 
-        if (mKeyboardAccessoryCoordinator != null) {
-            mKeyboardAccessoryCoordinator.destroy();
-            mKeyboardAccessoryCoordinator = null;
+        if (mManualFillingController != null) {
+            mManualFillingController.destroy();
+            mManualFillingController = null;
         }
 
         AccessibilityManager manager = (AccessibilityManager)

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessoryPagerAdapter.java

+// Copyright 2018 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.autofill.keyboard_accessory;
+
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v4.view.PagerAdapter;
+import android.support.v4.view.ViewPager;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import org.chromium.chrome.browser.modelutil.SimpleListObservable;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * This {@link PagerAdapter} renders an observable list of {@link KeyboardAccessoryData.Tab}s into a
+ * {@link ViewPager}. It instantiates the tab views based on the layout they provide.
+ */
+class AccessoryPagerAdapter extends PagerAdapter {
+    private final SimpleListObservable<KeyboardAccessoryData.Tab> mTabList;
+    private final Map<KeyboardAccessoryData.Tab, ViewGroup> mViews;
+
+    /**
+     * Creates the PagerAdapter that populates a ViewPager based on a held list of tabs.
+     * @param tabList The list that contains the tabs to instantiate.
+     */
+    public AccessoryPagerAdapter(SimpleListObservable<KeyboardAccessoryData.Tab> tabList) {
+        mTabList = tabList;
+        mViews = new HashMap<>(mTabList.getItemCount());
+    }
+
+    @NonNull
+    @Override
+    public Object instantiateItem(@NonNull ViewGroup container, int position) {
+        KeyboardAccessoryData.Tab tab = mTabList.get(position);
+        ViewGroup layout = mViews.get(tab);
+        if (layout == null) {
+            layout = (ViewGroup) LayoutInflater.from(container.getContext())
+                             .inflate(tab.getTabLayout(), container, false);
+            mViews.put(tab, layout);
+            if (container.indexOfChild(layout) == -1) container.addView(layout);
+            if (tab.getListener() != null) {
+                tab.getListener().onTabCreated(layout);
+            }
+        }
+        return layout;
+    }
+
+    @Override
+    public void destroyItem(@NonNull ViewGroup container, int position, @Nullable Object object) {
+        if (mViews.get(mTabList.get(position)) == null) return;
+        ViewGroup layout = mViews.get(mTabList.get(position));
+        if (container.indexOfChild(layout) != -1) container.removeView(layout);
+    }
+
+    @Override
+    public int getCount() {
+        return mTabList.getItemCount();
+    }
+
+    @Override
+    public boolean isViewFromObject(@NonNull View view, @NonNull Object o) {
+        return view == o;
+    }
+}

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessorySheetCoordinator.java

@@ -4,7 +4,9 @@
 
 package org.chromium.chrome.browser.autofill.keyboard_accessory;
 
-import android.view.View;
+import android.support.annotation.Nullable;
+import android.support.v4.view.PagerAdapter;
+import android.support.v4.view.ViewPager;
 import android.view.ViewStub;
 
 import org.chromium.base.VisibleForTesting;
@@ -14,7 +16,7 @@ import org.chromium.chrome.browser.modelutil.PropertyModelChangeProcessor;
 /**
  * Creates and owns all elements which are part of the accessory sheet component.
  * It's part of the controller but will mainly forward events (like showing the sheet) and handle
- * communication with the {@link ManualFillingController} (e.g. add a tab to trigger the sheet).
+ * communication with the {@link ManualFillingCoordinator} (e.g. add a tab to trigger the sheet).
  * to the {@link AccessorySheetMediator}.
  */
 public class AccessorySheetCoordinator {
@@ -26,7 +28,7 @@ public class AccessorySheetCoordinator {
      * @param viewStub The view stub that can be inflated into the accessory layout.
      */
     public AccessorySheetCoordinator(ViewStub viewStub) {
-        LazyViewBinderAdapter.StubHolder<View> stubHolder =
+        LazyViewBinderAdapter.StubHolder<ViewPager> stubHolder =
                 new LazyViewBinderAdapter.StubHolder<>(viewStub);
         AccessorySheetModel model = new AccessorySheetModel();
         model.addObserver(new PropertyModelChangeProcessor<>(
@@ -34,10 +36,34 @@ public class AccessorySheetCoordinator {
         mMediator = new AccessorySheetMediator(model);
     }
 
+    /**
+     * Creates the {@link PagerAdapter} for the newly inflated {@link ViewPager}.
+     * If any ListModelChangeProcessor<> is needed, it would be created here. Currently, connecting
+     * the model.getTabList() to the tabViewBinder would have no effect as only the change of
+     * ACTIVE_TAB affects the view.
+     * @param model The model containing the list of tabs to be displayed.
+     * @return A fully initialized {@link PagerAdapter}.
+     */
+    static PagerAdapter createTabViewAdapter(AccessorySheetModel model) {
+        return new AccessoryPagerAdapter(model.getTabList());
+    }
+
+    /**
+     * Adds the contents of a given {@link KeyboardAccessoryData.Tab} to the accessory sheet. If it
+     * is the first Tab, it automatically becomes the active Tab.
+     * Careful, if you want to show this tab as icon in the KeyboardAccessory, use the method
+     * {@link ManualFillingCoordinator#addTab(KeyboardAccessoryData.Tab)} instead.
+     * @param tab The tab which should be added to the AccessorySheet.
+     */
+    void addTab(KeyboardAccessoryData.Tab tab) {
+        mMediator.addTab(tab);
+    }
+
     /**
      * Returns a {@link KeyboardAccessoryData.Tab} object that is used to display this bottom sheet.
      * @return Returns a {@link KeyboardAccessoryData.Tab}.
      */
+    @Nullable
     public KeyboardAccessoryData.Tab getTab() {
         return mMediator.getTab();
     }

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessorySheetMediator.java

@@ -4,6 +4,8 @@
 
 package org.chromium.chrome.browser.autofill.keyboard_accessory;
 
+import android.support.annotation.Nullable;
+
 import org.chromium.base.VisibleForTesting;
 
 /**
@@ -12,14 +14,15 @@ import org.chromium.base.VisibleForTesting;
  */
 class AccessorySheetMediator {
     private final AccessorySheetModel mModel;
-    private KeyboardAccessoryData.Tab mTab;
 
     AccessorySheetMediator(AccessorySheetModel model) {
         mModel = model;
     }
 
+    @Nullable
     KeyboardAccessoryData.Tab getTab() {
-        return null; // TODO(fhorschig): Return the active tab.
+        if (mModel.getActiveTabIndex() == AccessorySheetModel.NO_ACTIVE_TAB) return null;
+        return mModel.getTabList().get(mModel.getActiveTabIndex());
     }
 
     @VisibleForTesting
@@ -34,4 +37,11 @@ class AccessorySheetMediator {
     public void hide() {
         mModel.setVisible(false);
     }
+
+    public void addTab(KeyboardAccessoryData.Tab tab) {
+        mModel.getTabList().add(tab);
+        if (mModel.getActiveTabIndex() == AccessorySheetModel.NO_ACTIVE_TAB) {
+            mModel.setActiveTabIndex(mModel.getTabList().getItemCount() - 1);
+        }
+    }
 }
\ No newline at end of file

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessorySheetModel.java

@@ -4,7 +4,9 @@
 
 package org.chromium.chrome.browser.autofill.keyboard_accessory;
 
+import org.chromium.chrome.browser.autofill.keyboard_accessory.KeyboardAccessoryData.Tab;
 import org.chromium.chrome.browser.modelutil.PropertyObservable;
+import org.chromium.chrome.browser.modelutil.SimpleListObservable;
 
 /**
  * This model holds all view state of the accessory sheet.
@@ -12,10 +14,22 @@ import org.chromium.chrome.browser.modelutil.PropertyObservable;
  * like the view binder react.
  */
 class AccessorySheetModel extends PropertyObservable<AccessorySheetModel.PropertyKey> {
-    public static class PropertyKey { public static final PropertyKey VISIBLE = new PropertyKey(); }
+    public static class PropertyKey {
+        public static final PropertyKey ACTIVE_TAB_INDEX = new PropertyKey();
+        public static final PropertyKey VISIBLE = new PropertyKey();
+    }
+
+    public static final int NO_ACTIVE_TAB = -1;
+
+    private int mActiveTabIndex = NO_ACTIVE_TAB;
     private boolean mVisible;
+    private final SimpleListObservable<Tab> mTabList = new SimpleListObservable<>();
+
+    SimpleListObservable<Tab> getTabList() {
+        return mTabList;
+    }
 
-    public void setVisible(boolean visible) {
+    void setVisible(boolean visible) {
         if (mVisible == visible) return; // Nothing to do here: same value.
         mVisible = visible;
         notifyPropertyChanged(PropertyKey.VISIBLE);
@@ -24,4 +38,17 @@ class AccessorySheetModel extends PropertyObservable<AccessorySheetModel.Propert
     boolean isVisible() {
         return mVisible;
     }
+
+    int getActiveTabIndex() {
+        return mActiveTabIndex;
+    }
+
+    void setActiveTabIndex(int activeTabPosition) {
+        if (mActiveTabIndex == activeTabPosition) return;
+        assert((activeTabPosition >= 0 && activeTabPosition < mTabList.getItemCount())
+                || activeTabPosition == NO_ACTIVE_TAB)
+            : "Tried to set invalid index '" + activeTabPosition + "' as active tab!";
+        mActiveTabIndex = activeTabPosition;
+        notifyPropertyChanged(PropertyKey.ACTIVE_TAB_INDEX);
+    }
 }
\ No newline at end of file

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessorySheetViewBinder.java

@@ -4,6 +4,7 @@
 
 package org.chromium.chrome.browser.autofill.keyboard_accessory;
 
+import android.support.v4.view.ViewPager;
 import android.view.View;
 
 import org.chromium.chrome.browser.autofill.keyboard_accessory.AccessorySheetModel.PropertyKey;
@@ -14,7 +15,8 @@ import org.chromium.chrome.browser.modelutil.LazyViewBinderAdapter;
  * {@link AccessorySheetViewBinder} which will modify the view accordingly.
  */
 class AccessorySheetViewBinder
-        implements LazyViewBinderAdapter.SimpleViewBinder<AccessorySheetModel, View, PropertyKey> {
+        implements LazyViewBinderAdapter
+                           .SimpleViewBinder<AccessorySheetModel, ViewPager, PropertyKey> {
     @Override
     public PropertyKey getVisibilityProperty() {
         return PropertyKey.VISIBLE;
@@ -26,14 +28,23 @@ class AccessorySheetViewBinder
     }
 
     @Override
-    public void onInitialInflation(AccessorySheetModel model, View inflatedView) {}
+    public void onInitialInflation(AccessorySheetModel model, ViewPager inflatedView) {
+        if (model.getActiveTabIndex() != -1) inflatedView.setCurrentItem(model.getActiveTabIndex());
+        inflatedView.setAdapter(AccessorySheetCoordinator.createTabViewAdapter(model));
+    }
 
     @Override
-    public void bind(AccessorySheetModel model, View inflatedView, PropertyKey propertyKey) {
+    public void bind(AccessorySheetModel model, ViewPager inflatedView, PropertyKey propertyKey) {
         if (propertyKey == PropertyKey.VISIBLE) {
             inflatedView.setVisibility(model.isVisible() ? View.VISIBLE : View.GONE);
             return;
         }
+        if (propertyKey == PropertyKey.ACTIVE_TAB_INDEX) {
+            if (model.getActiveTabIndex() != AccessorySheetModel.NO_ACTIVE_TAB) {
+                inflatedView.setCurrentItem(model.getActiveTabIndex());
+            }
+            return;
+        }
         assert false : "Every possible property update needs to be handled!";
     }
 }

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/KeyboardAccessoryCoordinator.java

@@ -16,6 +16,7 @@ import org.chromium.chrome.browser.modelutil.ListModelChangeProcessor;
 import org.chromium.chrome.browser.modelutil.PropertyModelChangeProcessor;
 import org.chromium.chrome.browser.modelutil.RecyclerViewAdapter;
 import org.chromium.chrome.browser.modelutil.RecyclerViewModelChangeProcessor;
+import org.chromium.chrome.browser.modelutil.SimpleListObservable;
 import org.chromium.ui.UiUtils;
 import org.chromium.ui.base.WindowAndroid;
 
@@ -49,12 +50,11 @@ public class KeyboardAccessoryCoordinator {
      * @param model the {@link KeyboardAccessoryModel} the adapter gets its data from.
      * @return Returns a fully initialized and wired adapter to an ActionViewBinder.
      */
-    static RecyclerViewAdapter<KeyboardAccessoryModel.SimpleListObservable<Action>,
-            ActionViewBinder.ViewHolder>
+    static RecyclerViewAdapter<SimpleListObservable<Action>, ActionViewBinder.ViewHolder>
     createActionsAdapter(KeyboardAccessoryModel model) {
-        RecyclerViewAdapter<KeyboardAccessoryModel.SimpleListObservable<Action>,
-                ActionViewBinder.ViewHolder> actionsAdapter =
-                new RecyclerViewAdapter<>(model.getActionList(), new ActionViewBinder());
+        RecyclerViewAdapter<SimpleListObservable<Action>, ActionViewBinder.ViewHolder>
+                actionsAdapter =
+                        new RecyclerViewAdapter<>(model.getActionList(), new ActionViewBinder());
         model.addActionListObserver(new RecyclerViewModelChangeProcessor<>(actionsAdapter));
         return actionsAdapter;
     }
@@ -79,7 +79,7 @@ public class KeyboardAccessoryCoordinator {
      * the start of the accessory. It is meant to trigger various bottom sheets.
      * @param tab The tab which contains representation data and links back to a bottom sheet.
      */
-    public void addTab(KeyboardAccessoryData.Tab tab) {
+    void addTab(KeyboardAccessoryData.Tab tab) {
         mMediator.addTab(tab);
     }
 
@@ -88,7 +88,7 @@ public class KeyboardAccessoryCoordinator {
      * from the accessory.
      * @param tab The tab to be removed.
      */
-    public void removeTab(KeyboardAccessoryData.Tab tab) {
+    void removeTab(KeyboardAccessoryData.Tab tab) {
         mMediator.removeTab(tab);
     }
 

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/KeyboardAccessoryData.java

@@ -5,6 +5,9 @@
 package org.chromium.chrome.browser.autofill.keyboard_accessory;
 
 import android.graphics.drawable.Drawable;
+import android.support.annotation.LayoutRes;
+import android.support.annotation.Nullable;
+import android.view.ViewGroup;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -46,6 +49,17 @@ public class KeyboardAccessoryData {
      * accessory. Typically, a tab is responsible to change the bottom sheet below the accessory.
      */
     public interface Tab {
+        /**
+         * A Tab's Listener get's notified when e.g. the Tab was assigned a view.
+         */
+        interface Listener {
+            /**
+             * Triggered when the tab was successfully created.
+             * @param view The newly created accessory sheet of the tab.
+             */
+            void onTabCreated(ViewGroup view);
+        }
+
         /**
          * Provides the icon that will be displayed in the {@link KeyboardAccessoryCoordinator}.
          * @return The small icon that identifies this tab uniquely.
@@ -57,6 +71,20 @@ public class KeyboardAccessoryData {
          * @return A short string describing the task of this tab.
          */
         String getContentDescription();
+
+        /**
+         * Returns the tab layout which allows to create the tab's view on demand.
+         * @return The layout resource that allows to create the view necessary for this tab.
+         */
+        @LayoutRes
+        int getTabLayout();
+
+        /**
+         * Returns the listener which might need to react on changes to this tab.
+         * @return A {@link Listener} to be called, e.g. when the tab is created.
+         */
+        @Nullable
+        Listener getListener();
     }
 
     /**

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/KeyboardAccessoryModel.java

@@ -7,9 +7,9 @@ package org.chromium.chrome.browser.autofill.keyboard_accessory;
 import org.chromium.chrome.browser.autofill.AutofillKeyboardSuggestions;
 import org.chromium.chrome.browser.modelutil.ListObservable;
 import org.chromium.chrome.browser.modelutil.PropertyObservable;
+import org.chromium.chrome.browser.modelutil.SimpleListObservable;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 
 /**
@@ -34,53 +34,6 @@ class KeyboardAccessoryModel extends PropertyObservable<KeyboardAccessoryModel.P
         }
     }
 
-    /** A {@link ListObservable} containing an {@link ArrayList} of Tabs or Actions. */
-    class SimpleListObservable<T> extends ListObservable {
-        private final List<T> mItems = new ArrayList<>();
-
-        public T get(int index) {
-            return mItems.get(index);
-        }
-
-        @Override
-        public int getItemCount() {
-            return mItems.size();
-        }
-
-        void add(T item) {
-            mItems.add(item);
-            notifyItemRangeInserted(mItems.size() - 1, 1);
-        }
-
-        void remove(T item) {
-            int position = mItems.indexOf(item);
-            if (position == -1) {
-                return;
-            }
-            mItems.remove(position);
-            notifyItemRangeRemoved(position, 1);
-        }
-
-        void set(T[] newItems) {
-            if (mItems.isEmpty()) {
-                if (newItems.length == 0) {
-                    return; // Nothing to do, nothing changes.
-                }
-                mItems.addAll(Arrays.asList(newItems));
-                notifyItemRangeInserted(0, mItems.size());
-                return;
-            }
-            int oldSize = mItems.size();
-            mItems.clear();
-            if (newItems.length == 0) {
-                notifyItemRangeRemoved(0, oldSize);
-                return;
-            }
-            mItems.addAll(Arrays.asList(newItems));
-            notifyItemRangeChanged(0, Math.max(oldSize, mItems.size()), this);
-        }
-    }
-
     private SimpleListObservable<KeyboardAccessoryData.Action> mActionListObservable;
     private SimpleListObservable<KeyboardAccessoryData.Tab> mTabListObservable;
     private boolean mVisible;

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/KeyboardAccessoryViewBinder.java

@@ -15,6 +15,7 @@ import org.chromium.chrome.browser.autofill.keyboard_accessory.KeyboardAccessory
 import org.chromium.chrome.browser.modelutil.LazyViewBinderAdapter;
 import org.chromium.chrome.browser.modelutil.ListModelChangeProcessor;
 import org.chromium.chrome.browser.modelutil.RecyclerViewAdapter;
+import org.chromium.chrome.browser.modelutil.SimpleListObservable;
 import org.chromium.ui.widget.ButtonCompat;
 
 /**
@@ -24,8 +25,9 @@ import org.chromium.ui.widget.ButtonCompat;
 class KeyboardAccessoryViewBinder
         implements LazyViewBinderAdapter.SimpleViewBinder<KeyboardAccessoryModel,
                 KeyboardAccessoryView, PropertyKey> {
-    static class ActionViewBinder implements RecyclerViewAdapter.ViewBinder<
-            KeyboardAccessoryModel.SimpleListObservable<Action>, ActionViewBinder.ViewHolder> {
+    static class ActionViewBinder
+            implements RecyclerViewAdapter.ViewBinder<SimpleListObservable<Action>,
+                    ActionViewBinder.ViewHolder> {
         static class ViewHolder extends RecyclerView.ViewHolder {
             public ViewHolder(ButtonCompat actionView) {
                 super(actionView);
@@ -44,8 +46,8 @@ class KeyboardAccessoryViewBinder
         }
 
         @Override
-        public void onBindViewHolder(KeyboardAccessoryModel.SimpleListObservable<Action> actions,
-                ViewHolder holder, int position) {
+        public void onBindViewHolder(
+                SimpleListObservable<Action> actions, ViewHolder holder, int position) {
             final Action action = actions.get(position);
             holder.getActionView().setText(action.getCaption());
             holder.getActionView().setOnClickListener(
@@ -53,11 +55,12 @@ class KeyboardAccessoryViewBinder
         }
     }
 
-    static class TabViewBinder implements ListModelChangeProcessor.ViewBinder<
-            KeyboardAccessoryModel.SimpleListObservable<Tab>, KeyboardAccessoryView> {
+    static class TabViewBinder
+            implements ListModelChangeProcessor
+                               .ViewBinder<SimpleListObservable<Tab>, KeyboardAccessoryView> {
         @Override
-        public void onItemsInserted(KeyboardAccessoryModel.SimpleListObservable<Tab> model,
-                KeyboardAccessoryView view, int index, int count) {
+        public void onItemsInserted(
+                SimpleListObservable<Tab> model, KeyboardAccessoryView view, int index, int count) {
             assert count > 0 : "Tried to insert invalid amount of tabs - must be at least one.";
             while (count-- > 0) {
                 Tab tab = model.get(index);
@@ -67,8 +70,8 @@ class KeyboardAccessoryViewBinder
         }
 
         @Override
-        public void onItemsRemoved(KeyboardAccessoryModel.SimpleListObservable<Tab> model,
-                KeyboardAccessoryView view, int index, int count) {
+        public void onItemsRemoved(
+                SimpleListObservable<Tab> model, KeyboardAccessoryView view, int index, int count) {
             assert count > 0 : "Tried to remove invalid amount of tabs - must be at least one.";
             while (count-- > 0) {
                 view.removeTabAt(index++);
@@ -76,14 +79,13 @@ class KeyboardAccessoryViewBinder
         }
 
         @Override
-        public void onItemsChanged(KeyboardAccessoryModel.SimpleListObservable<Tab> model,
-                KeyboardAccessoryView view, int index, int count) {
+        public void onItemsChanged(
+                SimpleListObservable<Tab> model, KeyboardAccessoryView view, int index, int count) {
             // TODO(fhorschig): Implement fine-grained, ranged changes should the need arise.
             updateAllTabs(view, model);
         }
 
-        void updateAllTabs(KeyboardAccessoryView view,
-                KeyboardAccessoryModel.SimpleListObservable<Tab> model) {
+        void updateAllTabs(KeyboardAccessoryView view, SimpleListObservable<Tab> model) {
             view.clearTabs();
             for (int i = 0; i < model.getItemCount(); ++i) {
                 Tab tab = model.get(i);

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/ManualFillingController.java

-// Copyright 2018 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.autofill.keyboard_accessory;
-
-// TODO(fhorschig): Inline this class if the setting up/destroying is less overhead than expected.
-// TODO(fhorschig): Otherwise, replace the KeyboardAccessorySheet in the ChromeActivity.
-/**
- * Handles requests to the manual UI for filling passwords, payments and other user data. Ideally,
- * the caller has no access to Keyboard accessory or sheet and is only interacting with this
- * component.
- * For that, it facilitates the communication between {@link KeyboardAccessoryCoordinator} and
- * {@link AccessorySheetCoordinator} to add and trigger surfaces that may assist users while filling
- * fields.
- */
-public class ManualFillingController {
-    private final KeyboardAccessoryCoordinator mKeyboardAccessoryCoordinator;
-
-    /**
-     * Creates a the manual filling controller.
-     * @param keyboardAccessoryCoordinator The keybaord
-     */
-    public ManualFillingController(KeyboardAccessoryCoordinator keyboardAccessoryCoordinator) {
-        mKeyboardAccessoryCoordinator = keyboardAccessoryCoordinator;
-    }
-
-    /**
-     * Links an {@link AccessorySheetCoordinator} to the {@link KeyboardAccessoryCoordinator}.
-     * @param accessorySheetCoordinator The sheet component to be linked.
-     */
-    public void addAccessorySheet(AccessorySheetCoordinator accessorySheetCoordinator) {
-        mKeyboardAccessoryCoordinator.addTab(accessorySheetCoordinator.getTab());
-    }
-}
\ No newline at end of file

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/ManualFillingCoordinator.java

+// Copyright 2018 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.autofill.keyboard_accessory;
+
+import android.view.ViewStub;
+
+import org.chromium.base.VisibleForTesting;
+import org.chromium.ui.base.WindowAndroid;
+
+/**
+ * Handles requests to the manual UI for filling passwords, payments and other user data. Ideally,
+ * the caller has no access to Keyboard accessory or sheet and is only interacting with this
+ * component.
+ * For that, it facilitates the communication between {@link KeyboardAccessoryCoordinator} and
+ * {@link AccessorySheetCoordinator} to add and trigger surfaces that may assist users while filling
+ * fields.
+ */
+public class ManualFillingCoordinator {
+    private final KeyboardAccessoryCoordinator mKeyboardAccessory;
+    private final AccessorySheetCoordinator mAccessorySheet;
+
+    /**
+     * Creates a the manual filling controller.
+     * @param windowAndroid The window needed to set up the sub components.
+     * @param keyboardAccessoryStub The view stub for keyboard accessory bar.
+     * @param accessorySheetStub The view stub for the keyboard accessory bottom sheet.
+     */
+    public ManualFillingCoordinator(WindowAndroid windowAndroid, ViewStub keyboardAccessoryStub,
+            ViewStub accessorySheetStub) {
+        mKeyboardAccessory = new KeyboardAccessoryCoordinator(windowAndroid, keyboardAccessoryStub);
+        mAccessorySheet = new AccessorySheetCoordinator(accessorySheetStub);
+    }
+
+    /**
+     * Cleans up the manual UI by destroying the accessory bar and its bottom sheet.
+     */
+    public void destroy() {
+        mKeyboardAccessory.destroy();
+    }
+
+    /**
+     * Links a tab to the manual UI by adding it to the held {@link AccessorySheetCoordinator} and
+     * the {@link KeyboardAccessoryCoordinator}.
+     * @param tab The tab component to be added.
+     */
+    public void addTab(KeyboardAccessoryData.Tab tab) {
+        mKeyboardAccessory.addTab(tab);
+        mAccessorySheet.addTab(tab);
+    }
+
+    /**
+     * Allows access to the keyboard accessory. This can be used to explicitly modify the the bar of
+     * the keyboard accessory (e.g. by providing suggestions or actions).
+     * @return The coordinator of the Keyboard accessory component.
+     */
+    public KeyboardAccessoryCoordinator getKeyboardAccessory() {
+        return mKeyboardAccessory;
+    }
+
+    /**
+     * Allows access to the accessory sheet.
+     * @return The coordinator of the Accessory sheet component.
+     */
+    @VisibleForTesting
+    public AccessorySheetCoordinator getAccessorySheetForTesting() {
+        return mAccessorySheet;
+    }
+}
\ No newline at end of file

chrome/android/java/src/org/chromium/chrome/browser/modelutil/SimpleListObservable.java

+// Copyright 2018 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.modelutil;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * A {@link ListObservable} containing an {@link ArrayList} of Tabs or Actions.
+ * It allows models to compose different ListObservables.
+ * @param <T> The object type that this class manages in a list.
+ */
+public class SimpleListObservable<T> extends ListObservable {
+    private final List<T> mItems = new ArrayList<>();
+
+    /**
+     * Returns the item at the given position.
+     * @param index The position to get the item from.
+     * @return Returns the found item.
+     */
+    public T get(int index) {
+        return mItems.get(index);
+    }
+
+    @Override
+    public int getItemCount() {
+        return mItems.size();
+    }
+
+    /**
+     * Appends a given item to the last position of the held {@link ArrayList}. Notifies observers
+     * about the inserted item.
+     * @param item The item to be stored.
+     */
+    public void add(T item) {
+        mItems.add(item);
+        notifyItemRangeInserted(mItems.size() - 1, 1);
+    }
+
+    /**
+     * Removes a given item from the held {@link ArrayList}. Notifies observers about the removal.
+     * @param item The item to be removed.
+     */
+    public void remove(T item) {
+        int position = mItems.indexOf(item);
+        mItems.remove(position);
+        notifyItemRangeRemoved(position, 1);
+    }
+
+    /**
+     * Replaces all held items with the given array of items.
+     * If the held list was empty, notify observers about inserted elements.
+     * If the held list isn't empty but the new list is, notify observer about the removal.
+     * If the new and old list aren't empty, notify observer about the complete exchange.
+     * @param newItems The set of items that should replace all held items.
+     */
+    public void set(T[] newItems) {
+        if (mItems.isEmpty()) {
+            if (newItems.length == 0) {
+                return; // Nothing to do, nothing changes.
+            }
+            mItems.addAll(Arrays.asList(newItems));
+            notifyItemRangeInserted(0, mItems.size());
+            return;
+        }
+        int oldSize = mItems.size();
+        mItems.clear();
+        if (newItems.length == 0) {
+            notifyItemRangeRemoved(0, oldSize);
+            return;
+        }
+        mItems.addAll(Arrays.asList(newItems));
+        notifyItemRangeChanged(0, Math.max(oldSize, mItems.size()), this);
+    }
+}
\ No newline at end of file

chrome/android/java_sources.gni

@@ -97,6 +97,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/autofill/PasswordGenerationPopupBridge.java",
   "java/src/org/chromium/chrome/browser/autofill/PersonalDataManager.java",
   "java/src/org/chromium/chrome/browser/autofill/PhoneNumberUtil.java",
+  "java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessoryPagerAdapter.java",
   "java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessorySheetCoordinator.java",
   "java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessorySheetMediator.java",
   "java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessorySheetModel.java",
@@ -107,7 +108,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/KeyboardAccessoryModel.java",
   "java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/KeyboardAccessoryView.java",
   "java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/KeyboardAccessoryViewBinder.java",
-  "java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/ManualFillingController.java",
+  "java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/ManualFillingCoordinator.java",
   "java/src/org/chromium/chrome/browser/background_task_scheduler/NativeBackgroundTask.java",
   "java/src/org/chromium/chrome/browser/banners/AppBannerManager.java",
   "java/src/org/chromium/chrome/browser/banners/AppBannerUiDelegateAndroid.java",
@@ -710,6 +711,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/modelutil/PropertyObservable.java",
   "java/src/org/chromium/chrome/browser/modelutil/RecyclerViewModelChangeProcessor.java",
   "java/src/org/chromium/chrome/browser/modelutil/RecyclerViewAdapter.java",
+  "java/src/org/chromium/chrome/browser/modelutil/SimpleListObservable.java",
   "java/src/org/chromium/chrome/browser/mojo/ChromeInterfaceRegistrar.java",
   "java/src/org/chromium/chrome/browser/multiwindow/MultiInstanceChromeTabbedActivity.java",
   "java/src/org/chromium/chrome/browser/multiwindow/MultiWindowUtils.java",
@@ -2038,6 +2040,7 @@ chrome_junit_test_java_sources = [
   "junit/src/org/chromium/chrome/browser/media/ui/MediaNotificationTestTabHolder.java",
   "junit/src/org/chromium/chrome/browser/media/ui/MediaNotificationTitleUpdatedTest.java",
   "junit/src/org/chromium/chrome/browser/metrics/VariationsSessionTest.java",
+  "junit/src/org/chromium/chrome/browser/modelutil/SimpleListObservableTest.java",
   "junit/src/org/chromium/chrome/browser/notifications/NotificationPlatformBridgeUnitTest.java",
   "junit/src/org/chromium/chrome/browser/notifications/channels/ChannelDefinitionsTest.java",
   "junit/src/org/chromium/chrome/browser/ntp/NativePageFactoryTest.java",

chrome/android/javatests/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessorySheetViewTest.java

@@ -4,13 +4,23 @@
 
 package org.chromium.chrome.browser.autofill.keyboard_accessory;
 
+import static android.support.test.espresso.Espresso.onView;
+import static android.support.test.espresso.assertion.ViewAssertions.matches;
+import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static android.support.test.espresso.matcher.ViewMatchers.withText;
+
 import static junit.framework.Assert.assertNotNull;
 import static junit.framework.Assert.assertNull;
 
 import static org.junit.Assert.assertTrue;
 
+import android.graphics.drawable.Drawable;
+import android.support.annotation.LayoutRes;
 import android.support.test.filters.MediumTest;
+import android.support.v4.view.ViewPager;
 import android.view.View;
+import android.widget.LinearLayout;
+import android.widget.TextView;
 
 import org.junit.Before;
 import org.junit.Rule;
@@ -34,7 +44,7 @@ import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 @CommandLineFlags.Add({ChromeSwitches.DISABLE_FIRST_RUN_EXPERIENCE})
 public class AccessorySheetViewTest {
     private AccessorySheetModel mModel;
-    private LazyViewBinderAdapter.StubHolder<View> mStubHolder;
+    private LazyViewBinderAdapter.StubHolder<ViewPager> mStubHolder;
 
     @Rule
     public ChromeActivityTestRule<ChromeTabbedActivity> mActivityTestRule =
@@ -66,4 +76,51 @@ public class AccessorySheetViewTest {
         assertNotNull(mStubHolder.getView());
         assertTrue(mStubHolder.getView().getVisibility() != View.VISIBLE);
     }
+
+    @Test
+    @MediumTest
+    public void testAddingTabToModelRendersTabsView() {
+        final String kSampleAction = "Some Action";
+        mModel.getTabList().add(createTestTab(view -> {
+            assertNotNull("The tab must have been created!", view);
+            assertTrue("Empty tab is a layout.", view instanceof LinearLayout);
+            LinearLayout baseLayout = (LinearLayout) view;
+            TextView sampleTextView = new TextView(mActivityTestRule.getActivity());
+            sampleTextView.setText(kSampleAction);
+            baseLayout.addView(sampleTextView);
+        }));
+        mModel.setActiveTabIndex(0);
+        // Shouldn't cause the view to be inflated.
+        assertNull(mStubHolder.getView());
+
+        // Setting visibility should cause the Tab to be rendered.
+        ThreadUtils.runOnUiThreadBlocking(() -> mModel.setVisible(true));
+        assertNotNull(mStubHolder.getView());
+
+        onView(withText(kSampleAction)).check(matches(isDisplayed()));
+    }
+
+    private KeyboardAccessoryData.Tab createTestTab(KeyboardAccessoryData.Tab.Listener listener) {
+        return new KeyboardAccessoryData.Tab() {
+            @Override
+            public Drawable getIcon() {
+                return null; // Unused.
+            }
+
+            @Override
+            public String getContentDescription() {
+                return null; // Unused.
+            }
+
+            @Override
+            public @LayoutRes int getTabLayout() {
+                return R.layout.empty_accessory_sheet;
+            }
+
+            @Override
+            public Listener getListener() {
+                return listener;
+            }
+        };
+    }
 }
\ No newline at end of file

chrome/android/javatests/src/org/chromium/chrome/browser/autofill/keyboard_accessory/KeyboardAccessoryViewTest.java

@@ -90,6 +90,16 @@ public class KeyboardAccessoryViewTest {
             public String getContentDescription() {
                 return contentDescription;
             }
+
+            @Override
+            public int getTabLayout() {
+                return R.layout.empty_accessory_sheet; // Unused.
+            }
+
+            @Override
+            public Listener getListener() {
+                return null; // Unused.
+            }
         };
     }
 

chrome/android/junit/src/org/chromium/chrome/browser/autofill/keyboard_accessory/AccessorySheetControllerTest.java

@@ -6,14 +6,15 @@ package org.chromium.chrome.browser.autofill.keyboard_accessory;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.CoreMatchers.notNullValue;
+import static org.hamcrest.CoreMatchers.nullValue;
 import static org.junit.Assert.assertThat;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import android.support.test.filters.SmallTest;
+import android.support.v4.view.ViewPager;
 import android.view.ViewStub;
-import android.widget.LinearLayout;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -24,6 +25,8 @@ import org.robolectric.annotation.Config;
 
 import org.chromium.base.test.BaseRobolectricTestRunner;
 import org.chromium.base.test.util.Feature;
+import org.chromium.chrome.browser.autofill.keyboard_accessory.AccessorySheetModel.PropertyKey;
+import org.chromium.chrome.browser.modelutil.ListObservable;
 import org.chromium.chrome.browser.modelutil.PropertyObservable;
 
 /**
@@ -33,12 +36,17 @@ import org.chromium.chrome.browser.modelutil.PropertyObservable;
 @Config(manifest = Config.NONE)
 public class AccessorySheetControllerTest {
     @Mock
-    private PropertyObservable
-            .PropertyObserver<AccessorySheetModel.PropertyKey> mMockPropertyObserver;
+    private PropertyObservable.PropertyObserver<PropertyKey> mMockPropertyObserver;
+    @Mock
+    private ListObservable.ListObserver mTabListObserver;
     @Mock
     private ViewStub mMockViewStub;
     @Mock
-    private LinearLayout mMockView;
+    private ViewPager mMockView;
+    @Mock
+    private KeyboardAccessoryData.Tab mMockTab;
+    @Mock
+    private KeyboardAccessoryData.Tab mSecondMockTab;
 
     private AccessorySheetCoordinator mCoordinator;
     private AccessorySheetMediator mMediator;
@@ -69,19 +77,54 @@ public class AccessorySheetControllerTest {
 
         // Calling show on the mediator should make model propagate that it's visible.
         mMediator.show();
-        verify(mMockPropertyObserver)
-                .onPropertyChanged(mModel, AccessorySheetModel.PropertyKey.VISIBLE);
+        verify(mMockPropertyObserver).onPropertyChanged(mModel, PropertyKey.VISIBLE);
         assertThat(mModel.isVisible(), is(true));
 
         // Calling show again does nothing.
         mMediator.show();
         verify(mMockPropertyObserver) // Still the same call and no new one added.
-                .onPropertyChanged(mModel, AccessorySheetModel.PropertyKey.VISIBLE);
+                .onPropertyChanged(mModel, PropertyKey.VISIBLE);
 
         // Calling hide on the mediator should make model propagate that it's invisible.
         mMediator.hide();
-        verify(mMockPropertyObserver, times(2))
-                .onPropertyChanged(mModel, AccessorySheetModel.PropertyKey.VISIBLE);
+        verify(mMockPropertyObserver, times(2)).onPropertyChanged(mModel, PropertyKey.VISIBLE);
         assertThat(mModel.isVisible(), is(false));
     }
+
+    @Test
+    @SmallTest
+    @Feature({"keyboard-accessory"})
+    public void testModelNotifiesChangesForNewSheet() {
+        mModel.addObserver(mMockPropertyObserver);
+        mModel.getTabList().addObserver(mTabListObserver);
+
+        assertThat(mModel.getTabList().getItemCount(), is(0));
+        mCoordinator.addTab(mMockTab);
+        verify(mTabListObserver).onItemRangeInserted(mModel.getTabList(), 0, 1);
+        assertThat(mModel.getTabList().getItemCount(), is(1));
+    }
+
+    @Test
+    @SmallTest
+    @Feature({"keyboard-accessory"})
+    public void testFirstAddedTabBecomesActiveTab() {
+        mModel.addObserver(mMockPropertyObserver);
+
+        // Initially, there is no active Tab.
+        assertThat(mModel.getTabList().getItemCount(), is(0));
+        assertThat(mCoordinator.getTab(), is(nullValue()));
+
+        // The first tab becomes the active Tab.
+        mCoordinator.addTab(mMockTab);
+        verify(mMockPropertyObserver).onPropertyChanged(mModel, PropertyKey.ACTIVE_TAB_INDEX);
+        assertThat(mModel.getTabList().getItemCount(), is(1));
+        assertThat(mModel.getActiveTabIndex(), is(0));
+        assertThat(mCoordinator.getTab(), is(mMockTab));
+
+        // A second tab is added but doesn't become automatically active.
+        mCoordinator.addTab(mSecondMockTab);
+        verify(mMockPropertyObserver).onPropertyChanged(mModel, PropertyKey.ACTIVE_TAB_INDEX);
+        assertThat(mModel.getTabList().getItemCount(), is(2));
+        assertThat(mModel.getActiveTabIndex(), is(0));
+    }
 }
\ No newline at end of file

chrome/android/junit/src/org/chromium/chrome/browser/autofill/keyboard_accessory/KeyboardAccessoryControllerTest.java

@@ -119,7 +119,7 @@ public class KeyboardAccessoryControllerTest {
         mCoordinator.addTab(mMockTab);
         verify(mMockTabListObserver).onItemRangeInserted(mModel.getTabList(), 0, 1);
         assertThat(mModel.getTabList().getItemCount(), is(1));
-        assertThat(mModel.getTabList().get(0), is(equalTo(mMockTab)));
+        assertThat(mModel.getTabList().get(0), is(mMockTab));
 
         // Calling hide on the coordinator should make model propagate that it's invisible.
         mCoordinator.removeTab(mMockTab);

chrome/android/junit/src/org/chromium/chrome/browser/autofill/keyboard_accessory/ManualFillingControllerTest.java

@@ -38,36 +38,43 @@ public class ManualFillingControllerTest {
     private KeyboardAccessoryView mMockView;
     @Mock
     private ListObservable.ListObserver mMockTabListObserver;
+    @Mock
+    private KeyboardAccessoryData.Tab mMockTab;
 
-    private KeyboardAccessoryCoordinator mKeyboardAccessory;
-    private ManualFillingController mController;
+    private ManualFillingCoordinator mController;
 
     @Before
     public void setUp() {
         MockitoAnnotations.initMocks(this);
         when(mMockViewStub.inflate()).thenReturn(mMockView);
-        mKeyboardAccessory = new KeyboardAccessoryCoordinator(mMockWindow, mMockViewStub);
-        mController = new ManualFillingController(mKeyboardAccessory);
+        mController = new ManualFillingCoordinator(mMockWindow, mMockViewStub, mMockViewStub);
     }
 
     @Test
     @SmallTest
     public void testCreatesValidSubComponents() {
-        assertThat(mKeyboardAccessory, is(notNullValue()));
         assertThat(mController, is(notNullValue()));
+        assertThat(mController.getKeyboardAccessory(), is(notNullValue()));
+        assertThat(mController.getAccessorySheetForTesting(), is(notNullValue()));
     }
 
     @Test
     @SmallTest
-    public void testAddingBottomSheetsAddsTabsToAccessory() {
+    public void testAddingNewTabIsAddedToAccessoryAndSheet() {
         KeyboardAccessoryModel keyboardAccessoryModel =
-                mKeyboardAccessory.getMediatorForTesting().getModelForTesting();
+                mController.getKeyboardAccessory().getMediatorForTesting().getModelForTesting();
         keyboardAccessoryModel.addTabListObserver(mMockTabListObserver);
+        AccessorySheetModel accessorySheetModel = mController.getAccessorySheetForTesting()
+                                                          .getMediatorForTesting()
+                                                          .getModelForTesting();
+        accessorySheetModel.getTabList().addObserver(mMockTabListObserver);
 
         assertThat(keyboardAccessoryModel.getTabList().getItemCount(), is(0));
-        mController.addAccessorySheet(new AccessorySheetCoordinator(mMockViewStub));
+        mController.addTab(mMockTab);
 
         verify(mMockTabListObserver).onItemRangeInserted(keyboardAccessoryModel.getTabList(), 0, 1);
+        verify(mMockTabListObserver).onItemRangeInserted(accessorySheetModel.getTabList(), 0, 1);
         assertThat(keyboardAccessoryModel.getTabList().getItemCount(), is(1));
+        assertThat(accessorySheetModel.getTabList().getItemCount(), is(1));
     }
 }
\ No newline at end of file

chrome/android/junit/src/org/chromium/chrome/browser/modelutil/OWNERS

+file://chrome/android/java/src/org/chromium/chrome/browser/modelutil/OWNERS

chrome/android/junit/src/org/chromium/chrome/browser/modelutil/SimpleListObservableTest.java

+// Copyright 2018 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.modelutil;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Mockito.verify;
+
+import android.support.test.filters.SmallTest;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+
+import org.chromium.base.test.BaseRobolectricTestRunner;
+import org.chromium.base.test.util.Feature;
+
+/**
+ * Basic test ensuring the {@link SimpleListObservable} notifies listeners properly.
+ */
+@RunWith(BaseRobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class SimpleListObservableTest {
+    @Mock
+    private ListObservable.ListObserver mObserver;
+
+    private SimpleListObservable<Integer> mIntegerList = new SimpleListObservable<>();
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mIntegerList.addObserver(mObserver);
+    }
+
+    @After
+    public void tearDown() {
+        mIntegerList.removeObserver(mObserver);
+    }
+
+    @Test
+    @SmallTest
+    @Feature({"keyboard-accessory"})
+    public void testNotifiesSuccessfulInsertions() {
+        // Setting an empty list ist always an insertion.
+        assertThat(mIntegerList.getItemCount(), is(0));
+        mIntegerList.set(new Integer[] {333, 88888888, 22});
+        verify(mObserver).onItemRangeInserted(mIntegerList, 0, 3);
+        assertThat(mIntegerList.getItemCount(), is(3));
+        assertThat(mIntegerList.get(1), is(88888888));
+
+        // Adding Items is always an insertion.
+        mIntegerList.add(55555);
+        verify(mObserver).onItemRangeInserted(mIntegerList, 3, 1);
+        assertThat(mIntegerList.getItemCount(), is(4));
+        assertThat(mIntegerList.get(3), is(55555));
+    }
+
+    @Test
+    @SmallTest
+    @Feature({"keyboard-accessory"})
+    public void testModelNotifiesSuccessfulRemoval() {
+        Integer eightEights = 88888888;
+        mIntegerList.set(new Integer[] {333, eightEights, 22});
+        assertThat(mIntegerList.getItemCount(), is(3));
+
+        // Removing any item by instance is always a removal.
+        mIntegerList.remove(eightEights);
+        verify(mObserver).onItemRangeRemoved(mIntegerList, 1, 1);
+
+        // Setting an empty list is a removal of all items.
+        mIntegerList.set(new Integer[] {});
+        verify(mObserver).onItemRangeRemoved(mIntegerList, 0, 2);
+    }
+
+    @Test
+    @SmallTest
+    @Feature({"keyboard-accessory"})
+    public void testModelNotifiesReplacedData() {
+        // The initial setting is an insertion.
+        mIntegerList.set(new Integer[] {333, 88888888, 22});
+        verify(mObserver).onItemRangeInserted(mIntegerList, 0, 3);
+
+        // Setting non-empty data is a change of all elements.
+        mIntegerList.set(new Integer[] {4444, 22});
+        verify(mObserver).onItemRangeChanged(mIntegerList, 0, 3, mIntegerList);
+
+        // Setting data of same values is a change.
+        mIntegerList.set(new Integer[] {4444, 22, 1, 666666});
+        verify(mObserver).onItemRangeChanged(mIntegerList, 0, 4, mIntegerList);
+
+        // Setting empty data is a removal.
+        mIntegerList.set(new Integer[] {});
+        verify(mObserver).onItemRangeRemoved(mIntegerList, 0, 4);
+    }
+}
\ No newline at end of file