[StartSurface] Introduce fake search box

This is the second patch of splitting the bigger one
https://chromium-review.googlesource.com/c/chromium/src/+/1797069

It depends on
https://chromium-review.googlesource.com/c/chromium/src/+/1817106

Screenshots
https://drive.google.com/file/d/1FBGZygqGDlFA2e1Mr_81HAVWpzn_1-yc/view?usp=sharing

Additional design discussion context:
https://docs.google.com/document/d/1Igy8tZll_WtZyg7c5lxWzOYuxb3OGzJ39YcBW_em37s/edit?usp=sharing

Bug: 982018
Change-Id: Ib93ae336cd77eb89296ed5cb68b2b62f5b45b94d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1822820
Commit-Queue: Ganggui Tang <gogerald@chromium.org>
Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
Auto-Submit: Ganggui Tang <gogerald@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702978}

chrome/android/features/start_surface/internal/BUILD.gn

@@ -89,6 +89,7 @@ android_library("java") {
     "java/src/org/chromium/chrome/features/start_surface/StartSurfaceLayout.java",
     "java/src/org/chromium/chrome/features/start_surface/StartSurfaceMediator.java",
     "java/src/org/chromium/chrome/features/start_surface/StartSurfaceProperties.java",
+    "java/src/org/chromium/chrome/features/start_surface/StartSurfaceLocationBarDelegate.java",
     "java/src/org/chromium/chrome/features/start_surface/SecondaryTasksSurfaceViewBinder.java",
     "java/src/org/chromium/chrome/features/start_surface/TasksSurfaceViewBinder.java",
   ]

chrome/android/features/start_surface/internal/java/src/org/chromium/chrome/features/start_surface/StartSurfaceCoordinator.java

@@ -75,6 +75,10 @@ public class StartSurfaceCoordinator implements StartSurface {
     @Nullable
     private TabSwitcher.OnTabSelectingListener mOnTabSelectingListener;
 
+    // Non-null in SurfaceMode.TASKS_ONLY, SurfaceMode.TWO_PANES and SurfaceMode.SINGLE_PANE modes.
+    @Nullable
+    private StartSurfaceLocationBarDelegate mStartSurfaceLocationBarDelegate;
+
     public StartSurfaceCoordinator(ChromeActivity activity) {
         mActivity = activity;
         mSurfaceMode = computeSurfaceMode();
@@ -96,10 +100,15 @@ public class StartSurfaceCoordinator implements StartSurface {
                         : mExploreSurfaceCoordinator.getFeedSurfaceCreator(),
                 mSurfaceMode == SurfaceMode.SINGLE_PANE ? this::initializeSecondaryTasksSurface
                                                         : null,
-                mSurfaceMode);
+                mSurfaceMode, mStartSurfaceLocationBarDelegate);
     }
 
     // Implements StartSurface.
+    @Override
+    public void setStateChangeObserver(StartSurface.StateObserver observer) {
+        mStartSurfaceMediator.setStateChangeObserver(observer);
+    }
+
     @Override
     public void setOnTabSelectingListener(StartSurface.OnTabSelectingListener listener) {
         if (mTasksSurface != null) {
@@ -158,8 +167,12 @@ public class StartSurfaceCoordinator implements StartSurface {
         mPropertyModel.set(TOP_BAR_HEIGHT,
                 mActivity.getResources().getDimensionPixelSize(R.dimen.toolbar_height_no_shadow));
 
-        mTasksSurface = TabManagementModuleProvider.getDelegate().createTasksSurface(
-                mActivity, mSurfaceMode == SurfaceMode.SINGLE_PANE, mPropertyModel);
+        // TODO(crbug.com/1000295): Formalize the way to get the location bar.
+        mStartSurfaceLocationBarDelegate = new StartSurfaceLocationBarDelegate(
+                mActivity.getToolbarManager().getToolbarLayoutForTesting().getLocationBar());
+        mTasksSurface = TabManagementModuleProvider.getDelegate().createTasksSurface(mActivity,
+                mPropertyModel, mStartSurfaceLocationBarDelegate,
+                mSurfaceMode == SurfaceMode.SINGLE_PANE);
 
         // The tasks surface is added to the explore surface in the single pane mode below.
         if (mSurfaceMode != SurfaceMode.SINGLE_PANE) {
@@ -191,11 +204,12 @@ public class StartSurfaceCoordinator implements StartSurface {
     private TabSwitcher.Controller initializeSecondaryTasksSurface() {
         assert mSurfaceMode == SurfaceMode.SINGLE_PANE;
         assert mSecondaryTasksSurface == null;
+        assert mStartSurfaceLocationBarDelegate != null;
 
         PropertyModel propertyModel = new PropertyModel(TasksSurfaceProperties.ALL_KEYS);
         mStartSurfaceMediator.setSecondaryTasksSurfacePropertyModel(propertyModel);
         mSecondaryTasksSurface = TabManagementModuleProvider.getDelegate().createTasksSurface(
-                mActivity, false, propertyModel);
+                mActivity, propertyModel, mStartSurfaceLocationBarDelegate, false);
         mSecondaryTasksSurfacePropertyModelChangeProcessor =
                 createTasksViewPropertyModelChangeProcessor(
                         mSecondaryTasksSurface.getContainerView(),

chrome/android/features/start_surface/internal/java/src/org/chromium/chrome/features/start_surface/StartSurfaceLocationBarDelegate.java

+// Copyright 2019 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.features.start_surface;
+
+import androidx.annotation.Nullable;
+
+import org.chromium.chrome.browser.omnibox.LocationBar;
+import org.chromium.chrome.browser.omnibox.UrlFocusChangeListener;
+import org.chromium.chrome.browser.tasks.TasksSurface;
+
+/** The delegate to interact with the {@link LocationBar}. */
+class StartSurfaceLocationBarDelegate
+        implements TasksSurface.FakeSearchBoxDelegate, StartSurfaceMediator.Delegate {
+    private final LocationBar mLocationBar;
+
+    StartSurfaceLocationBarDelegate(LocationBar locationBar) {
+        mLocationBar = locationBar;
+    }
+
+    // Implements TasksSurface.FakeSearchBoxDelegate.
+    @Override
+    public void requestUrlFocus(@Nullable String pastedText) {
+        mLocationBar.setUrlBarFocus(true);
+    }
+
+    // Implements StartSurfaceMediator.Delegate.
+    @Override
+    public void addUrlFocusChangeListener(UrlFocusChangeListener listener) {
+        mLocationBar.addUrlFocusChangeListener(listener);
+    }
+
+    @Override
+    public void removeUrlFocusChangeListener(UrlFocusChangeListener listener) {
+        mLocationBar.removeUrlFocusChangeListener(listener);
+    }
+}

chrome/android/features/start_surface/internal/java/src/org/chromium/chrome/features/start_surface/StartSurfaceMediator.java

@@ -4,6 +4,7 @@
 
 package org.chromium.chrome.features.start_surface;
 
+import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.IS_FAKE_SEARCH_BOX_VISIBLE;
 import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.MORE_TABS_CLICK_LISTENER;
 import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.MV_TILES_VISIBLE;
 import static org.chromium.chrome.features.start_surface.StartSurfaceProperties.BOTTOM_BAR_CLICKLISTENER;
@@ -25,10 +26,10 @@ import org.chromium.base.ContextUtils;
 import org.chromium.base.ObserverList;
 import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.chrome.browser.feed.FeedSurfaceCoordinator;
+import org.chromium.chrome.browser.omnibox.UrlFocusChangeListener;
 import org.chromium.chrome.browser.tabmodel.EmptyTabModelSelectorObserver;
 import org.chromium.chrome.browser.tabmodel.TabModel;
 import org.chromium.chrome.browser.tabmodel.TabModelSelector;
-import org.chromium.chrome.browser.tasks.ReturnToChromeExperimentsUtil;
 import org.chromium.chrome.browser.tasks.tab_management.TabSwitcher;
 import org.chromium.chrome.start_surface.R;
 import org.chromium.ui.modelutil.PropertyModel;
@@ -49,6 +50,21 @@ class StartSurfaceMediator
         int SINGLE_PANE = 3;
     }
 
+    /** The delegate to interact with the location bar. */
+    interface Delegate {
+        /**
+         * Add the given url focus change listener.
+         * @param listener The given listener.
+         */
+        void addUrlFocusChangeListener(UrlFocusChangeListener listener);
+
+        /**
+         * Remove the given url focus change listener.
+         * @param listener The given listener.
+         */
+        void removeUrlFocusChangeListener(UrlFocusChangeListener listener);
+    }
+
     /** Interface to initialize a secondary tasks surface for more tabs. */
     interface SecondaryTasksSurfaceInitializer {
         /**
@@ -74,21 +90,29 @@ class StartSurfaceMediator
     @Nullable
     private PropertyModel mSecondaryTasksSurfacePropertyModel;
     private boolean mIsIncognito;
+    @Nullable
+    private Delegate mDelegate;
+    @Nullable
+    UrlFocusChangeListener mUrlFocusChangeListener;
+    @Nullable
+    private StartSurface.StateObserver mStateObserver;
 
     StartSurfaceMediator(TabSwitcher.Controller controller, TabModelSelector tabModelSelector,
             @Nullable PropertyModel propertyModel,
             @Nullable ExploreSurfaceCoordinator.FeedSurfaceCreator feedSurfaceCreator,
             @Nullable SecondaryTasksSurfaceInitializer secondaryTasksSurfaceInitializer,
-            @SurfaceMode int surfaceMode) {
+            @SurfaceMode int surfaceMode, @Nullable Delegate delegate) {
         mController = controller;
         mPropertyModel = propertyModel;
         mFeedSurfaceCreator = feedSurfaceCreator;
         mSecondaryTasksSurfaceInitializer = secondaryTasksSurfaceInitializer;
         mSurfaceMode = surfaceMode;
+        mDelegate = delegate;
 
         if (mPropertyModel != null) {
             assert mSurfaceMode == SurfaceMode.SINGLE_PANE || mSurfaceMode == SurfaceMode.TWO_PANES
                     || mSurfaceMode == SurfaceMode.TASKS_ONLY;
+            assert mDelegate != null;
 
             mIsIncognito = tabModelSelector.isIncognitoSelected();
             tabModelSelector.addObserver(new EmptyTabModelSelectorObserver() {
@@ -107,6 +131,7 @@ class StartSurfaceMediator
                         @Override
                         public void onHomeButtonClicked() {
                             setExploreSurfaceVisibility(false);
+                            notifyStateChange();
                             RecordUserAction.record("StartSurface.TwoPanes.BottomBar.TapHome");
                         }
 
@@ -115,6 +140,7 @@ class StartSurfaceMediator
                             // TODO(crbug.com/982018): Hide the Tab switcher toolbar when showing
                             // explore surface.
                             setExploreSurfaceVisibility(true);
+                            notifyStateChange();
                             RecordUserAction.record(
                                     "StartSurface.TwoPanes.BottomBar.TapExploreSurface");
                         }
@@ -144,10 +170,23 @@ class StartSurfaceMediator
             int toolbarHeight =
                     ContextUtils.getApplicationContext().getResources().getDimensionPixelSize(
                             R.dimen.toolbar_height_no_shadow);
-            int topControlsHeight = ReturnToChromeExperimentsUtil.shouldShowOmniboxOnTabSwitcher()
-                    ? toolbarHeight * 2
-                    : toolbarHeight;
-            mPropertyModel.set(TOP_BAR_HEIGHT, topControlsHeight);
+            mPropertyModel.set(TOP_BAR_HEIGHT, toolbarHeight);
+
+            mUrlFocusChangeListener = new UrlFocusChangeListener() {
+                @Override
+                public void onUrlFocusChange(boolean hasFocus) {
+                    // No fake search box on the explore pane in two panes mode.
+                    if (mSurfaceMode != SurfaceMode.TWO_PANES
+                            || !mPropertyModel.get(IS_EXPLORE_SURFACE_VISIBLE)) {
+                        mPropertyModel.set(IS_FAKE_SEARCH_BOX_VISIBLE, !hasFocus);
+                    }
+                    if (mPropertyModel.get(IS_SECONDARY_SURFACE_VISIBLE)) {
+                        mSecondaryTasksSurfacePropertyModel.set(
+                                IS_FAKE_SEARCH_BOX_VISIBLE, !hasFocus);
+                    }
+                    notifyStateChange();
+                }
+            };
         }
         mController.addOverviewModeObserver(this);
     }
@@ -160,6 +199,10 @@ class StartSurfaceMediator
         mSecondaryTasksSurfacePropertyModel.set(MV_TILES_VISIBLE, false);
     }
 
+    void setStateChangeObserver(StartSurface.StateObserver observer) {
+        mStateObserver = observer;
+    }
+
     // Implements StartSurface.Controller
     @Override
     public boolean overviewVisible() {
@@ -214,7 +257,9 @@ class StartSurfaceMediator
                 mPropertyModel.set(FEED_SURFACE_COORDINATOR,
                         mFeedSurfaceCreator.createFeedSurfaceCoordinator());
             }
+
             mPropertyModel.set(IS_SHOWING_OVERVIEW, true);
+            mDelegate.addUrlFocusChangeListener(mUrlFocusChangeListener);
         }
 
         mController.showOverview(animate);
@@ -230,12 +275,14 @@ class StartSurfaceMediator
 
             setSecondaryTasksSurfaceVisibility(false);
             setExploreSurfaceVisibility(true);
+            notifyStateChange();
             return true;
         }
 
         if (mPropertyModel != null && mPropertyModel.get(IS_EXPLORE_SURFACE_VISIBLE)
                 && mSurfaceMode == SurfaceMode.TWO_PANES) {
             setExploreSurfaceVisibility(false);
+            notifyStateChange();
             return true;
         }
 
@@ -255,12 +302,20 @@ class StartSurfaceMediator
         for (StartSurface.OverviewModeObserver observer : mObservers) {
             observer.finishedShowing();
         }
+
+        // TODO(crbug.com/982018): Move to showOverview before overview is showing.
+        // Note that Tab switcher mode toolbar is lazily created when showing Tab switcher the first
+        // time.
+        if (mSurfaceMode != SurfaceMode.NO_START_SURFACE) {
+            notifyStateChange();
+        }
     }
 
     @Override
     public void startedHiding() {
         if (mPropertyModel != null) {
             mPropertyModel.set(IS_SHOWING_OVERVIEW, false);
+            mDelegate.removeUrlFocusChangeListener(mUrlFocusChangeListener);
             destroyFeedSurfaceCoordinator();
         }
         for (StartSurface.OverviewModeObserver observer : mObservers) {
@@ -275,6 +330,13 @@ class StartSurfaceMediator
         }
     }
 
+    private void destroyFeedSurfaceCoordinator() {
+        FeedSurfaceCoordinator feedSurfaceCoordinator =
+                mPropertyModel.get(FEED_SURFACE_COORDINATOR);
+        if (feedSurfaceCoordinator != null) feedSurfaceCoordinator.destroy();
+        mPropertyModel.set(FEED_SURFACE_COORDINATOR, null);
+    }
+
     // Implements View.OnClickListener, which listens for the more tabs button.
     @Override
     public void onClick(View v) {
@@ -332,22 +394,18 @@ class StartSurfaceMediator
             // always show the Home Pane, so the Explore Pane stays hidden.
             if (mIsIncognito) setExploreSurfaceVisibility(false);
         }
-    }
 
-    private void destroyFeedSurfaceCoordinator() {
-        FeedSurfaceCoordinator feedSurfaceCoordinator =
-                mPropertyModel.get(FEED_SURFACE_COORDINATOR);
-        if (feedSurfaceCoordinator != null) feedSurfaceCoordinator.destroy();
-        mPropertyModel.set(FEED_SURFACE_COORDINATOR, null);
+        notifyStateChange();
     }
 
     private void setSecondaryTasksSurfaceVisibility(boolean isVisible) {
         assert mSurfaceMode == SurfaceMode.SINGLE_PANE;
+
         if (isVisible) {
             if (mSecondaryTasksSurfaceController == null) {
                 mSecondaryTasksSurfaceController = mSecondaryTasksSurfaceInitializer.initialize();
             }
-
+            mSecondaryTasksSurfacePropertyModel.set(IS_FAKE_SEARCH_BOX_VISIBLE, mIsIncognito);
             mSecondaryTasksSurfaceController.showOverview(false);
         } else {
             if (mSecondaryTasksSurfaceController == null) return;
@@ -355,4 +413,34 @@ class StartSurfaceMediator
         }
         mPropertyModel.set(IS_SECONDARY_SURFACE_VISIBLE, isVisible);
     }
+
+    private void notifyStateChange() {
+        assert mSurfaceMode != SurfaceMode.NO_START_SURFACE;
+
+        if (mStateObserver != null) {
+            mStateObserver.onStateChanged(shouldShowTabSwitcherToolbar());
+        }
+    }
+
+    private boolean shouldShowTabSwitcherToolbar() {
+        if (mSurfaceMode == SurfaceMode.SINGLE_PANE) {
+            // Show Tab switcher toolbar when showing more Tabs and in incognito single pane when
+            // fake search box is visible.
+            if (mPropertyModel.get(IS_SECONDARY_SURFACE_VISIBLE)) {
+                return !mIsIncognito
+                        || (mIsIncognito
+                                && mSecondaryTasksSurfacePropertyModel.get(
+                                        IS_FAKE_SEARCH_BOX_VISIBLE));
+            }
+        }
+
+        // Do not show Tab switcher toolbar on explore pane.
+        if (mSurfaceMode == SurfaceMode.TWO_PANES
+                && mPropertyModel.get(IS_EXPLORE_SURFACE_VISIBLE)) {
+            return false;
+        }
+
+        // Do not show Tab switcher toolbar when focusing the Omnibox.
+        return mPropertyModel.get(IS_FAKE_SEARCH_BOX_VISIBLE);
+    }
 }

chrome/android/features/start_surface/public/java/src/org/chromium/chrome/features/start_surface/StartSurface.java

@@ -8,6 +8,25 @@ import org.chromium.chrome.browser.tasks.tab_management.TabSwitcher;
 
 /** Interface to communicate with the start surface. */
 public interface StartSurface {
+    /**
+     * An observer that is notified when the start surface internal state, excluding
+     * the states notified in {@link OverviewModeObserver}, is changed.
+     */
+    interface StateObserver {
+        /**
+         * Called when the internal state is changed.
+         * @param shouldShowTabSwitcherToolbar Whether or not should show the Tab switcher toolbar.
+         */
+        void onStateChanged(boolean shouldShowTabSwitcherToolbar);
+    }
+
+    /**
+     * Set the given {@link StateObserver}.
+     * Note that this will override the previous observer.
+     * @param observer The given observer.
+     */
+    void setStateChangeObserver(StateObserver observer);
+
     /**
      * Defines an interface to pass out tab selecting event.
      */

chrome/android/features/tab_ui/java/res/layout/tasks_view_layout.xml

@@ -10,6 +10,10 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical">
+
+    <!-- Search box -->
+    <include layout="@layout/fake_search_box_layout"/>
+
     <HorizontalScrollView android:id="@+id/mv_tiles_container"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
@@ -22,6 +26,7 @@
             android:orientation="horizontal"
             android:paddingBottom="@dimen/tasks_view_items_vertical_spacing" />
     </HorizontalScrollView>
+
     <LinearLayout
         android:id="@+id/tab_switcher_title"
         android:layout_width="match_parent"

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

@@ -6,6 +6,8 @@ package org.chromium.chrome.browser.tasks;
 
 import android.view.ViewGroup;
 
+import androidx.annotation.Nullable;
+
 import org.chromium.chrome.browser.compositor.layouts.Layout;
 import org.chromium.chrome.browser.tasks.tab_management.TabSwitcher;
 
@@ -15,6 +17,15 @@ import org.chromium.chrome.browser.tasks.tab_management.TabSwitcher;
  *  {@link TasksSurfaceCoordinator}.
  */
 public interface TasksSurface {
+    /** The delegate for the fake search box on the tasks surface. */
+    public interface FakeSearchBoxDelegate {
+        /**
+         * Interface to request focusing on the URL bar.
+         * @param pastedText The text to be pasted in the Omnibox or null.
+         * */
+        void requestUrlFocus(@Nullable String pastedText);
+    }
+
     /**
      * Set the listener to get the {@link Layout#onTabSelecting} event from the Grid Tab Switcher.
      * @param listener The {@link TabSwitcher.OnTabSelectingListener} to use.

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

@@ -26,8 +26,8 @@ public class TasksSurfaceCoordinator implements TasksSurface {
     private final MostVisitedListCoordinator mMostVisitedList;
     private final TasksSurfaceMediator mMediator;
 
-    public TasksSurfaceCoordinator(
-            ChromeActivity activity, boolean isTabCarousel, PropertyModel propertyModel) {
+    public TasksSurfaceCoordinator(ChromeActivity activity, PropertyModel propertyModel,
+            TasksSurface.FakeSearchBoxDelegate fakeSearchBoxDelegate, boolean isTabCarousel) {
         mView = (TasksView) LayoutInflater.from(activity).inflate(R.layout.tasks_view_layout, null);
         mPropertyModelChangeProcessor =
                 PropertyModelChangeProcessor.create(propertyModel, mView, TasksViewBinder::bind);
@@ -39,7 +39,8 @@ public class TasksSurfaceCoordinator implements TasksSurface {
                     activity, mView.getTabSwitcherContainer());
         }
 
-        mMediator = new TasksSurfaceMediator(activity, propertyModel, isTabCarousel);
+        mMediator = new TasksSurfaceMediator(
+                activity, propertyModel, fakeSearchBoxDelegate, isTabCarousel);
 
         LinearLayout mvTilesLayout = mView.findViewById(R.id.mv_tiles_layout);
         mMostVisitedList = new MostVisitedListCoordinator(activity, mvTilesLayout, propertyModel);

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

@@ -4,9 +4,14 @@
 
 package org.chromium.chrome.browser.tasks;
 
+import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.FAKE_SEARCH_BOX_CLICK_LISTENER;
+import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.IS_FAKE_SEARCH_BOX_VISIBLE;
 import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.IS_TAB_CAROUSEL;
+import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.IS_VOICE_RECOGNITION_BUTTON_VISIBLE;
 
 import android.content.Context;
+import android.support.annotation.Nullable;
+import android.view.View;
 
 import org.chromium.ui.modelutil.PropertyModel;
 
@@ -14,10 +19,30 @@ import org.chromium.ui.modelutil.PropertyModel;
  * Mediator for handling {@link TasksSurface}-related logic.
  */
 class TasksSurfaceMediator {
+    @Nullable
+    private final TasksSurface.FakeSearchBoxDelegate mFakeSearchBoxDelegate;
     private final PropertyModel mModel;
 
-    TasksSurfaceMediator(Context context, PropertyModel model, boolean isTabCarousel) {
+    TasksSurfaceMediator(Context context, PropertyModel model,
+            TasksSurface.FakeSearchBoxDelegate fakeSearchBoxDelegate, boolean isTabCarousel) {
+        mFakeSearchBoxDelegate = fakeSearchBoxDelegate;
+        assert mFakeSearchBoxDelegate != null;
+
         mModel = model;
         mModel.set(IS_TAB_CAROUSEL, isTabCarousel);
+        mModel.set(FAKE_SEARCH_BOX_CLICK_LISTENER, new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                mFakeSearchBoxDelegate.requestUrlFocus(null);
+            }
+        });
+
+        // Set the initial state.
+        mModel.set(IS_FAKE_SEARCH_BOX_VISIBLE, true);
+        mModel.set(IS_VOICE_RECOGNITION_BUTTON_VISIBLE, false);
+
+        // TODO(crbug.com/982018): Enable voice recognition button in the fake search box.
+        // TODO(crbug.com/982018): Enable long press and paste search in the fake search box.
+        // TODO(crbug.com/982018): Change the fake search box in incognito and dark mode.
     }
 }

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

@@ -15,12 +15,21 @@ import org.chromium.ui.modelutil.PropertyModel;
 public class TasksSurfaceProperties {
     private TasksSurfaceProperties() {}
 
+    public static final PropertyModel.WritableBooleanPropertyKey IS_FAKE_SEARCH_BOX_VISIBLE =
+            new PropertyModel.WritableBooleanPropertyKey();
     public static final PropertyModel.WritableBooleanPropertyKey IS_TAB_CAROUSEL =
             new PropertyModel.WritableBooleanPropertyKey();
+    public static final PropertyModel
+            .WritableBooleanPropertyKey IS_VOICE_RECOGNITION_BUTTON_VISIBLE =
+            new PropertyModel.WritableBooleanPropertyKey();
+    public static final PropertyModel
+            .WritableObjectPropertyKey<View.OnClickListener> FAKE_SEARCH_BOX_CLICK_LISTENER =
+            new PropertyModel.WritableObjectPropertyKey<View.OnClickListener>();
     public static final PropertyModel
             .WritableObjectPropertyKey<View.OnClickListener> MORE_TABS_CLICK_LISTENER =
             new PropertyModel.WritableObjectPropertyKey<View.OnClickListener>();
     public static final PropertyModel.WritableBooleanPropertyKey MV_TILES_VISIBLE = IS_VISIBLE;
-    public static final PropertyKey[] ALL_KEYS =
-            new PropertyKey[] {IS_TAB_CAROUSEL, MORE_TABS_CLICK_LISTENER, MV_TILES_VISIBLE};
+    public static final PropertyKey[] ALL_KEYS = new PropertyKey[] {IS_FAKE_SEARCH_BOX_VISIBLE,
+            IS_TAB_CAROUSEL, IS_VOICE_RECOGNITION_BUTTON_VISIBLE, FAKE_SEARCH_BOX_CLICK_LISTENER,
+            MORE_TABS_CLICK_LISTENER, MV_TILES_VISIBLE};
 }

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

@@ -59,6 +59,30 @@ class TasksView extends LinearLayout {
         }
     }
 
+    /**
+     * Set the given listener for the fake search box.
+     * @param listener The given listener.
+     */
+    void setFakeSearchBoxClickListener(@Nullable View.OnClickListener listener) {
+        findViewById(R.id.search_box_text).setOnClickListener(listener);
+    }
+
+    /**
+     * Set the visibility of the fake search box.
+     * @param isVisible Whether it's visible.
+     */
+    void setFakeSearchBoxVisibility(boolean isVisible) {
+        findViewById(R.id.search_box).setVisibility(isVisible ? View.VISIBLE : View.GONE);
+    }
+
+    /**
+     * Set the visibility of the voice recognition button.
+     * @param isVisible Whether it's visible.
+     */
+    void setVoiceRecognitionButtonVisibility(boolean isVisible) {
+        findViewById(R.id.voice_search_button).setVisibility(isVisible ? View.VISIBLE : View.GONE);
+    }
+
     /**
      * Set the visibility of the Most Visited Tiles.
      */

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

@@ -4,7 +4,10 @@
 
 package org.chromium.chrome.browser.tasks;
 
+import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.FAKE_SEARCH_BOX_CLICK_LISTENER;
+import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.IS_FAKE_SEARCH_BOX_VISIBLE;
 import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.IS_TAB_CAROUSEL;
+import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.IS_VOICE_RECOGNITION_BUTTON_VISIBLE;
 import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.MORE_TABS_CLICK_LISTENER;
 import static org.chromium.chrome.browser.tasks.TasksSurfaceProperties.MV_TILES_VISIBLE;
 
@@ -16,8 +19,15 @@ import org.chromium.ui.modelutil.PropertyModel;
 // The view binder of the tasks surface view.
 class TasksViewBinder {
     public static void bind(PropertyModel model, TasksView view, PropertyKey propertyKey) {
-        if (propertyKey == IS_TAB_CAROUSEL) {
+        if (propertyKey == FAKE_SEARCH_BOX_CLICK_LISTENER) {
+            view.setFakeSearchBoxClickListener(model.get(FAKE_SEARCH_BOX_CLICK_LISTENER));
+        } else if (propertyKey == IS_FAKE_SEARCH_BOX_VISIBLE) {
+            view.setFakeSearchBoxVisibility(model.get(IS_FAKE_SEARCH_BOX_VISIBLE));
+        } else if (propertyKey == IS_TAB_CAROUSEL) {
             view.setIsTabCarousel(model.get(IS_TAB_CAROUSEL));
+        } else if (propertyKey == IS_VOICE_RECOGNITION_BUTTON_VISIBLE) {
+            view.setVoiceRecognitionButtonVisibility(
+                    model.get(IS_VOICE_RECOGNITION_BUTTON_VISIBLE));
         } else if (propertyKey == MORE_TABS_CLICK_LISTENER) {
             view.setMoreTabsOnClickListener(model.get(MORE_TABS_CLICK_LISTENER));
         } else if (propertyKey == MV_TILES_VISIBLE) {

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

@@ -37,10 +37,7 @@ class TabListContainerProperties {
     public static final PropertyModel.WritableIntPropertyKey SHADOW_TOP_MARGIN =
             new PropertyModel.WritableIntPropertyKey();
 
-    public static final PropertyModel.WritableIntPropertyKey TOP_PADDING =
-            new PropertyModel.WritableIntPropertyKey();
-
     public static final PropertyKey[] ALL_KEYS = new PropertyKey[] {IS_VISIBLE, IS_INCOGNITO,
             VISIBILITY_LISTENER, INITIAL_SCROLL_INDEX, ANIMATE_VISIBILITY_CHANGES,
-            TOP_CONTROLS_HEIGHT, BOTTOM_CONTROLS_HEIGHT, SHADOW_TOP_MARGIN, TOP_PADDING};
+            TOP_CONTROLS_HEIGHT, BOTTOM_CONTROLS_HEIGHT, SHADOW_TOP_MARGIN};
 }

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

@@ -11,7 +11,6 @@ import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerP
 import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerProperties.IS_VISIBLE;
 import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerProperties.SHADOW_TOP_MARGIN;
 import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerProperties.TOP_CONTROLS_HEIGHT;
-import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerProperties.TOP_PADDING;
 import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerProperties.VISIBILITY_LISTENER;
 
 import android.support.v7.widget.LinearLayoutManager;
@@ -58,9 +57,6 @@ class TabListContainerViewBinder {
             view.requestLayout();
         } else if (SHADOW_TOP_MARGIN == propertyKey) {
             view.setShadowTopMargin(model.get(SHADOW_TOP_MARGIN));
-        } else if (TOP_PADDING == propertyKey) {
-            view.setPadding(view.getPaddingLeft(), model.get(TOP_PADDING), view.getPaddingRight(),
-                    view.getPaddingBottom());
         }
     }
 }

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

@@ -29,13 +29,14 @@ public interface TabManagementDelegate {
     /**
      * Create the {@link TasksSurface}
      * @param activity The {@link ChromeActivity} that creates this surface.
-     * @param isTabCarousel Whether show the Tabs in carousel mode.
      * @param propertyModel The {@link PropertyModel} contains the {@link TasksSurfaceProperties} to
      *         communicate with this surface.
+     * @param fakeSearchBoxDelegate The delegate of the fake search box.
+     * @param isTabCarousel Whether show the Tabs in carousel mode.
      * @return The {@TasksSurface}.
      */
-    TasksSurface createTasksSurface(
-            ChromeActivity activity, boolean isTabCarousel, PropertyModel propertyModel);
+    TasksSurface createTasksSurface(ChromeActivity activity, PropertyModel propertyModel,
+            TasksSurface.FakeSearchBoxDelegate fakeSearchBoxDelegate, boolean isTabCarousel);
 
     /**
      * Create the {@link TabSwitcher} to display Tabs in grid.

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

@@ -32,9 +32,10 @@ import org.chromium.ui.modelutil.PropertyModel;
 @UsedByReflection("TabManagementModule")
 public class TabManagementDelegateImpl implements TabManagementDelegate {
     @Override
-    public TasksSurface createTasksSurface(
-            ChromeActivity activity, boolean isTabCarousel, PropertyModel propertyModel) {
-        return new TasksSurfaceCoordinator(activity, isTabCarousel, propertyModel);
+    public TasksSurface createTasksSurface(ChromeActivity activity, PropertyModel propertyModel,
+            TasksSurface.FakeSearchBoxDelegate fakeSearchBoxDelegate, boolean isTabCarousel) {
+        return new TasksSurfaceCoordinator(
+                activity, propertyModel, fakeSearchBoxDelegate, isTabCarousel);
     }
 
     @Override

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

@@ -11,7 +11,6 @@ import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerP
 import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerProperties.IS_VISIBLE;
 import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerProperties.SHADOW_TOP_MARGIN;
 import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerProperties.TOP_CONTROLS_HEIGHT;
-import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerProperties.TOP_PADDING;
 import static org.chromium.chrome.browser.tasks.tab_management.TabListContainerProperties.VISIBILITY_LISTENER;
 
 import android.graphics.Bitmap;
@@ -249,10 +248,7 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
 
         // Container view takes care of padding and margin in start surface.
         if (mode != TabListCoordinator.TabListMode.CAROUSEL) {
-            // TODO(crbug.com/1010310): Remove the start surface check when tasks-only start surface
-            //  can replace the omnibox check.
             int topControlsHeight = ReturnToChromeExperimentsUtil.shouldShowOmniboxOnTabSwitcher()
-                            && FeatureUtilities.isStartSurfaceEnabled()
                     ? 0
                     : fullscreenManager.getTopControlsHeight();
             mContainerViewModel.set(TOP_CONTROLS_HEIGHT, topControlsHeight);
@@ -262,17 +258,9 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
             int toolbarHeight =
                     ContextUtils.getApplicationContext().getResources().getDimensionPixelSize(
                             R.dimen.toolbar_height_no_shadow);
-
-            if (ReturnToChromeExperimentsUtil.shouldShowOmniboxOnTabSwitcher()
-                    && !FeatureUtilities.isStartSurfaceEnabled()) {
-                // TODO(crbug.com/1010310): Remove this and the TOP_PADDING property once this can
-                //  be replaced by tasks-only start surface mode.
-                mContainerViewModel.set(TOP_PADDING, toolbarHeight);
-                mContainerViewModel.set(SHADOW_TOP_MARGIN, 2 * toolbarHeight);
-            } else {
-                mContainerViewModel.set(SHADOW_TOP_MARGIN,
-                        FeatureUtilities.isStartSurfaceEnabled() ? 0 : toolbarHeight);
-            }
+            mContainerViewModel.set(SHADOW_TOP_MARGIN,
+                    ReturnToChromeExperimentsUtil.shouldShowOmniboxOnTabSwitcher() ? 0
+                                                                                   : toolbarHeight);
         }
 
         mContainerView = containerView;

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

@@ -10,14 +10,6 @@
     android:layout_height="wrap_content"
     android:minHeight="@dimen/control_container_height" >
 
-    <ViewStub
-        android:id="@+id/tab_switcher_toolbar_stub"
-        android:layout_width="match_parent"
-        android:layout_marginTop="@dimen/tab_strip_height"
-        android:layout_height="@dimen/toolbar_height_no_shadow"
-        android:inflatedId="@+id/tab_switcher_toolbar"
-        android:layout="@layout/tab_switcher_toolbar" />
-
     <view
         class="org.chromium.chrome.browser.toolbar.top.ToolbarControlContainer$ToolbarViewResourceFrameLayout"
         android:id="@+id/toolbar_container"
@@ -57,4 +49,12 @@
             android:layout_gravity="end|top"
             android:layout="@layout/find_toolbar" />
     </view>
+
+    <ViewStub
+        android:id="@+id/tab_switcher_toolbar_stub"
+        android:layout_width="match_parent"
+        android:layout_marginTop="@dimen/tab_strip_height"
+        android:layout_height="@dimen/toolbar_height_no_shadow"
+        android:inflatedId="@+id/tab_switcher_toolbar"
+        android:layout="@layout/tab_switcher_toolbar" />
 </org.chromium.chrome.browser.toolbar.top.ToolbarControlContainer>

chrome/android/java/res/layout/fake_search_box_layout.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. -->
+
+<view
+    class="org.chromium.chrome.browser.ntp.NewTabPageLayout$SearchBoxContainerView"
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/search_box"
+    android:layout_width="match_parent"
+    android:layout_height="@dimen/ntp_search_box_height"
+    android:layout_marginStart="10dp"
+    android:layout_marginEnd="10dp"
+    android:layout_marginTop="0dp"
+    android:layout_marginBottom="1dp"
+    android:gravity="center_vertical"
+    android:addStatesFromChildren="true"
+    android:background="@drawable/ntp_search_box"
+    android:orientation="horizontal"
+    android:paddingStart="@dimen/location_bar_lateral_padding" >
+
+    <!-- TODO(crbug.com/900912): Fix and remove lint ignore -->
+    <EditText
+        tools:ignore="Autofill,LabelFor"
+        style="@style/TextAppearance.NewTabPageSearchBoxText"
+        android:id="@+id/search_box_text"
+        android:layout_width="0dp"
+        android:layout_height="match_parent"
+        android:layout_marginEnd="12dp"
+        android:layout_weight="1"
+        android:background="@null"
+        android:ellipsize="end"
+        android:focusableInTouchMode="false"
+        android:focusable="false"
+        android:gravity="center_vertical"
+        android:inputType="text"
+        android:singleLine="true"
+        android:hint="@string/search_or_type_web_address" />
+    <!-- Padding start is applied so that microphone icon appears in the same location as it
+        does in the main url bar. The microphone button in the url bar is 48dp wide with 4dp
+        start padding. -->
+    <org.chromium.ui.widget.ChromeImageView
+        android:id="@+id/voice_search_button"
+        android:layout_width="48dp"
+        android:layout_height="match_parent"
+        android:paddingStart="4dp"
+        android:contentDescription="@string/accessibility_toolbar_btn_mic"
+        android:src="@drawable/btn_mic"
+        android:scaleType="centerInside"
+        app:tint="@color/standard_mode_tint" />
+</view>

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

@@ -26,49 +26,7 @@
         android:layout_marginBottom="23dp" />
 
     <!-- Search box -->
-    <view
-        class="org.chromium.chrome.browser.ntp.NewTabPageLayout$SearchBoxContainerView"
-        android:id="@+id/search_box"
-        android:layout_width="match_parent"
-        android:layout_height="@dimen/ntp_search_box_height"
-        android:layout_marginStart="10dp"
-        android:layout_marginEnd="10dp"
-        android:layout_marginTop="0dp"
-        android:layout_marginBottom="1dp"
-        android:gravity="center_vertical"
-        android:addStatesFromChildren="true"
-        android:background="@drawable/ntp_search_box"
-        android:orientation="horizontal"
-        android:paddingStart="@dimen/location_bar_lateral_padding" >
-        <!-- TODO(crbug.com/900912): Fix and remove lint ignore -->
-        <EditText
-            tools:ignore="Autofill,LabelFor"
-            style="@style/TextAppearance.NewTabPageSearchBoxText"
-            android:id="@+id/search_box_text"
-            android:layout_width="0dp"
-            android:layout_height="match_parent"
-            android:layout_marginEnd="12dp"
-            android:layout_weight="1"
-            android:background="@null"
-            android:ellipsize="end"
-            android:focusableInTouchMode="false"
-            android:focusable="false"
-            android:gravity="center_vertical"
-            android:inputType="text"
-            android:singleLine="true" />
-        <!-- Padding start is applied so that microphone icon appears in the same location as it
-             does in the main url bar. The microphone button in the url bar is
-             48dp wide with 4dp start padding. -->
-        <org.chromium.ui.widget.ChromeImageView
-            android:id="@+id/voice_search_button"
-            android:layout_width="48dp"
-            android:layout_height="match_parent"
-            android:paddingStart="4dp"
-            android:contentDescription="@string/accessibility_toolbar_btn_mic"
-            android:src="@drawable/btn_mic"
-            android:scaleType="centerInside"
-            app:tint="@color/standard_mode_tint" />
-    </view>
+    <include layout="@layout/fake_search_box_layout"/>
 
     <!-- Middle spacer -->
     <View

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

@@ -386,6 +386,13 @@ public class ChromeTabbedActivity extends ChromeActivity implements ScreenshotMo
             }
         }
 
+        @Override
+        public void onOverviewModeStateChanged(boolean showTabSwitcherToolbar) {
+            for (OverviewModeObserver observer : mOverviewModeObserverList) {
+                observer.onOverviewModeStateChanged(showTabSwitcherToolbar);
+            }
+        }
+
         @Override
         public void onOverviewModeStartedHiding(boolean showToolbar, boolean delayAnimation) {
             for (OverviewModeObserver observer : mOverviewModeObserverList) {

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/EmptyOverviewModeObserver.java

@@ -16,6 +16,9 @@ public class EmptyOverviewModeObserver implements OverviewModeObserver {
     @Override
     public void onOverviewModeFinishedShowing() {}
 
+    @Override
+    public void onOverviewModeStateChanged(boolean showTabSwitcherToolbar) {}
+
     @Override
     public void onOverviewModeStartedHiding(boolean showToolbar, boolean delayAnimation) {}
 

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/LayoutManagerChrome.java

@@ -15,6 +15,7 @@ import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.chrome.browser.accessibility_tab_switcher.OverviewListLayout;
 import org.chromium.chrome.browser.compositor.TitleCache;
 import org.chromium.chrome.browser.compositor.bottombar.OverlayPanel.StateChangeReason;
+import org.chromium.chrome.browser.compositor.layouts.OverviewModeBehavior.OverviewModeObserver;
 import org.chromium.chrome.browser.compositor.layouts.components.LayoutTab;
 import org.chromium.chrome.browser.compositor.layouts.components.VirtualView;
 import org.chromium.chrome.browser.compositor.layouts.content.TabContentManager;
@@ -93,6 +94,14 @@ public class LayoutManagerChrome extends LayoutManager implements OverviewModeCo
                 TabManagementDelegate tabManagementDelegate =
                         TabManagementModuleProvider.getDelegate();
                 assert tabManagementDelegate != null;
+                startSurface.setStateChangeObserver(new StartSurface.StateObserver() {
+                    @Override
+                    public void onStateChanged(boolean shouldShowTabSwitcherToolbar) {
+                        for (OverviewModeObserver observer : mOverviewModeObservers) {
+                            observer.onOverviewModeStateChanged(shouldShowTabSwitcherToolbar);
+                        }
+                    }
+                });
                 mOverviewLayout = tabManagementDelegate.createStartSurfaceLayout(
                         context, this, renderHost, startSurface);
             } else {

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/OverviewModeBehavior.java

@@ -25,6 +25,12 @@ public interface OverviewModeBehavior {
          */
         void onOverviewModeFinishedShowing();
 
+        /**
+         * Called when the internal state is changed.
+         * @param showTabSwitcherToolbar Whether or not request showing the Tab switcher toolbar.
+         */
+        void onOverviewModeStateChanged(boolean showTabSwitcherToolbar);
+
         /**
          * Called when overview mode starts hiding.
          * @param showToolbar    Whether or not to show the normal toolbar when animating out of

chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageLayout.java

@@ -295,9 +295,6 @@ public class NewTabPageLayout extends LinearLayout implements TileGroup.Observer
         TraceEvent.begin(TAG + ".initializeSearchBoxTextView()");
 
         final TextView searchBoxTextView = mSearchBoxView.findViewById(R.id.search_box_text);
-        String hintText = getResources().getString(R.string.search_or_type_web_address);
-        searchBoxTextView.setHint(hintText);
-
         searchBoxTextView.setOnClickListener(v -> mManager.focusSearchBox(false, null));
         searchBoxTextView.addTextChangedListener(new TextWatcher() {
             @Override

chrome/android/java/src/org/chromium/chrome/browser/tasks/ReturnToChromeExperimentsUtil.java

@@ -59,14 +59,13 @@ public final class ReturnToChromeExperimentsUtil {
      * Whether we should display the omnibox on the tab switcher in addition to the
      *  tab switcher toolbar.
      *
-     * @return true if the tab switcher on return and tab grid features are both ON, else false.
+     * @return true if the tab grid and the start surface features are both ON, else false.
      */
     public static boolean shouldShowOmniboxOnTabSwitcher() {
         return ChromeFeatureList.isInitialized()
                 && (FeatureUtilities.isGridTabSwitcherEnabled()
                         || FeatureUtilities.isTabGroupsAndroidEnabled())
-                && (ChromeFeatureList.isEnabled(ChromeFeatureList.TAB_SWITCHER_ON_RETURN)
-                        || FeatureUtilities.isStartSurfaceEnabled());
+                && FeatureUtilities.isStartSurfaceEnabled();
     }
 
     /**

chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarManager.java

@@ -674,6 +674,11 @@ public class ToolbarManager implements ScrimObserver, ToolbarTabController, UrlF
                 updateButtonStatus();
             }
 
+            @Override
+            public void onOverviewModeStateChanged(boolean showTabSwitcherToolbar) {
+                mToolbar.updateTabSwitcherToolbarState(showTabSwitcherToolbar);
+            }
+
             @Override
             public void onOverviewModeStartedHiding(boolean showToolbar, boolean delayAnimation) {
                 mToolbar.setTabSwitcherMode(false, showToolbar, delayAnimation);

chrome/android/java/src/org/chromium/chrome/browser/toolbar/top/TabSwitcherModeTTCoordinatorPhone.java

@@ -163,22 +163,28 @@ class TabSwitcherModeTTCoordinatorPhone implements TemplateUrlServiceObserver {
     }
 
     void setTabSwitcherToolbarVisibility(boolean shouldShowTabSwitcherToolbar) {
-        final float targetAlpha = shouldShowTabSwitcherToolbar ? 1.0f : 0.0f;
+        if ((mTabSwitcherModeToolbar.getVisibility() == View.VISIBLE)
+                == shouldShowTabSwitcherToolbar) {
+            return;
+        }
 
+        final float targetAlpha = shouldShowTabSwitcherToolbar ? 1.0f : 0.0f;
         mTabSwitcherModeToolbar.animate()
                 .alpha(targetAlpha)
                 .setDuration(TopToolbarCoordinator.TAB_SWITCHER_MODE_NORMAL_ANIMATION_DURATION_MS)
                 .setListener(new AnimatorListenerAdapter() {
                     @Override
                     public void onAnimationStart(Animator animation) {
-                        if (shouldShowTabSwitcherToolbar)
+                        if (shouldShowTabSwitcherToolbar) {
                             mTabSwitcherModeToolbar.setVisibility(View.VISIBLE);
+                        }
                     }
 
                     @Override
                     public void onAnimationEnd(Animator animation) {
-                        if (!shouldShowTabSwitcherToolbar)
+                        if (!shouldShowTabSwitcherToolbar) {
                             mTabSwitcherModeToolbar.setVisibility(View.GONE);
+                        }
                     }
                 });
     }

chrome/android/java/src/org/chromium/chrome/browser/toolbar/top/TabSwitcherModeTTPhone.java

@@ -24,7 +24,6 @@ import org.chromium.chrome.browser.device.DeviceClassManager;
 import org.chromium.chrome.browser.preferences.PrefServiceBridge;
 import org.chromium.chrome.browser.tabmodel.TabModel;
 import org.chromium.chrome.browser.tabmodel.TabModelSelector;
-import org.chromium.chrome.browser.tasks.ReturnToChromeExperimentsUtil;
 import org.chromium.chrome.browser.toolbar.IncognitoStateProvider;
 import org.chromium.chrome.browser.toolbar.IncognitoToggleTabLayout;
 import org.chromium.chrome.browser.toolbar.MenuButton;
@@ -178,12 +177,6 @@ public class TabSwitcherModeTTPhone extends OptimizedFrameLayout
         } else {
             if (mNewTabImageButton != null) mNewTabImageButton.setEnabled(true);
             if (mNewTabViewButton != null) mNewTabViewButton.setEnabled(true);
-            if (ReturnToChromeExperimentsUtil.shouldShowOmniboxOnTabSwitcher()) {
-                // Bump this down by the height of the toolbar so the omnibox can be visible.
-                MarginLayoutParams params = (MarginLayoutParams) getLayoutParams();
-                params.topMargin =
-                        getResources().getDimensionPixelSize(R.dimen.toolbar_height_no_shadow);
-            }
         }
 
         mVisiblityAnimator.addListener(new CancelAwareAnimatorListener() {

chrome/android/java/src/org/chromium/chrome/browser/toolbar/top/Toolbar.java

@@ -114,4 +114,10 @@ public interface Toolbar {
      * @return The primary color to use for the background drawable.
      */
     int getPrimaryColor();
+
+    /**
+     * Update the Tab switcher toolbar state.
+     * @param requestToShow Whether or not request showing the Tab switcher toolbar.
+     */
+    void updateTabSwitcherToolbarState(boolean requestToShow);
 }

chrome/android/java/src/org/chromium/chrome/browser/toolbar/top/TopToolbarCoordinator.java

@@ -210,6 +210,17 @@ public class TopToolbarCoordinator implements Toolbar {
         return mToolbarLayout.getToolbarDataProvider().getPrimaryColor();
     }
 
+    @Override
+    public void updateTabSwitcherToolbarState(boolean requestToShow) {
+        if (mTabSwitcherModeCoordinatorPhone == null
+                || mToolbarLayout.getToolbarDataProvider() == null
+                || !mToolbarLayout.getToolbarDataProvider().isInOverviewAndShowingOmnibox()) {
+            return;
+        }
+
+        mTabSwitcherModeCoordinatorPhone.setTabSwitcherToolbarVisibility(requestToShow);
+    }
+
     @Override
     public void getPositionRelativeToContainer(View containerView, int[] position) {
         mToolbarLayout.getPositionRelativeToContainer(containerView, position);
@@ -482,12 +493,6 @@ public class TopToolbarCoordinator implements Toolbar {
      */
     public void onUrlFocusChange(boolean hasFocus) {
         mToolbarLayout.onUrlFocusChange(hasFocus);
-
-        if (mToolbarLayout.getToolbarDataProvider() != null
-                && mToolbarLayout.getToolbarDataProvider().isInOverviewAndShowingOmnibox()
-                && mTabSwitcherModeCoordinatorPhone != null) {
-            mTabSwitcherModeCoordinatorPhone.setTabSwitcherToolbarVisibility(!hasFocus);
-        }
     }
 
     /**