Add animation to history info header

+ Make DateDividedAdapter support multiple header items so that
  privacy disclaimers and clear browsing data button can be seperate
  items in recycler view to support show/hide animation.
+ Hide info button when info header is not visible on scrolling down
  in both history and downloads.
+ Remove header when history items are all deleted.

BUG=689322

Change-Id: Idbcae648ba277eb82b87bbe5a0667373bb09fc1a
Reviewed-on: https://chromium-review.googlesource.com/560672
Commit-Queue: Becky Zhou <huayinz@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488031}

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

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2017 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. -->
+
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content" />
\ No newline at end of file

chrome/android/java/res/layout/history_header.xml → chrome/android/java/res/layout/history_clear_browsing_data_header.xml

 <?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright 2016 The Chromium Authors. All rights reserved.
+<!-- Copyright 2017 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. -->
 
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
-    android:orientation="vertical"
-    android:layout_marginBottom="8dp" >
-
-    <LinearLayout
-        android:id="@+id/privacy_disclaimers"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:orientation="vertical"
-        android:layout_marginTop="8dp"
-        android:visibility="gone"
-        android:layout_marginBottom="16dp" >
-
-        <org.chromium.ui.widget.TextViewWithClickableSpans
-            android:id="@+id/signed_in_not_synced"
-            style="@style/PrivacyDisclaimerText" />
-
-       <org.chromium.ui.widget.TextViewWithClickableSpans
-            android:id="@+id/signed_in_synced"
-            style="@style/PrivacyDisclaimerText" />
-
-       <org.chromium.ui.widget.TextViewWithClickableSpans
-            android:id="@+id/other_forms_of_browsing_history"
-            style="@style/PrivacyDisclaimerText" />
-
-    </LinearLayout>
+    android:paddingBottom="8dp"
+    android:background="@null" >
 
     <FrameLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:background="@drawable/list_item_single" >
-
-        <!-- TODO(twellington): change start/end padding back to 16dp
-                                when new assets with correct built in padding
-                                are available. -->
+        <!-- TODO(twellington): change start/end padding back to 16dp and remove duplicate
+                                FrameLayout when list item background is removed. -->
         <Button
             android:id="@+id/clear_browsing_data_button"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
+            android:layout_gravity="top"
             style="@style/ButtonCompatBorderless"
             android:paddingTop="16dp"
             android:paddingBottom="16dp"
@@ -54,6 +30,5 @@
             android:textAllCaps="true"
             android:textColor="@color/blue_when_enabled"
             android:textSize="14sp" />
-
     </FrameLayout>
-</LinearLayout>
+</FrameLayout>
\ No newline at end of file

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

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2017 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. -->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="vertical"
+    android:paddingBottom="16dp" >
+
+    <org.chromium.ui.widget.TextViewWithClickableSpans
+        android:id="@+id/signed_in_not_synced"
+        style="@style/PrivacyDisclaimerText" />
+
+    <org.chromium.ui.widget.TextViewWithClickableSpans
+        android:id="@+id/signed_in_synced"
+        style="@style/PrivacyDisclaimerText" />
+
+    <org.chromium.ui.widget.TextViewWithClickableSpans
+        android:id="@+id/other_forms_of_browsing_history"
+        style="@style/PrivacyDisclaimerText" />
+
+    <Space
+        android:id="@+id/privacy_disclaimer_bottom_space"
+        android:layout_width="match_parent"
+        android:layout_height="8dp" />
+</LinearLayout>
\ No newline at end of file

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

@@ -21,6 +21,8 @@
             android:id="@+id/recycler_view"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
+            android:paddingTop="8dp"
+            android:clipToPadding="false"
             android:visibility="gone" />
 
         <TextView

chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java

@@ -9,6 +9,7 @@ import android.support.annotation.Nullable;
 import android.support.v7.widget.RecyclerView.ViewHolder;
 import android.text.TextUtils;
 import android.view.LayoutInflater;
+import android.view.View;
 import android.view.ViewGroup;
 
 import org.chromium.base.ContextUtils;
@@ -167,6 +168,7 @@ public class DownloadHistoryAdapter extends DateDividedAdapter
     private int mFilter = DownloadFilter.FILTER_ALL;
     private String mSearchQuery = EMPTY_QUERY;
     private SpaceDisplay mSpaceDisplay;
+    private HeaderItem mSpaceDisplayHeaderItem;
     private boolean mIsSearching;
     private boolean mShouldShowStorageInfoHeader;
 
@@ -191,6 +193,8 @@ public class DownloadHistoryAdapter extends DateDividedAdapter
         mBackendProvider = provider;
         mUiConfig = uiConfig;
 
+        generateHeaderItems();
+
         DownloadItemSelectionDelegate selectionDelegate =
                 (DownloadItemSelectionDelegate) mBackendProvider.getSelectionDelegate();
         selectionDelegate.initialize(this);
@@ -363,27 +367,31 @@ public class DownloadHistoryAdapter extends DateDividedAdapter
         holder.getItemView().displayItem(mBackendProvider, item);
     }
 
+    @Override
+    protected void bindViewHolderForHeaderItem(ViewHolder viewHolder, HeaderItem headerItem) {
+        super.bindViewHolderForHeaderItem(viewHolder, headerItem);
+        mSpaceDisplay.onChanged();
+    }
+
     @Override
     protected ItemGroup createGroup(long timeStamp) {
         return new DownloadItemGroup(timeStamp);
     }
 
-    @Override
-    protected BasicViewHolder createHeader(ViewGroup parent) {
-        if (mSpaceDisplay == null) {
-            mSpaceDisplay = new SpaceDisplay(parent, this);
-            registerAdapterDataObserver(mSpaceDisplay);
-            if (mUiConfig != null) {
-                MarginResizer.createAndAttach(mSpaceDisplay.getView(), mUiConfig,
-                        parent.getResources().getDimensionPixelSize(
-                                R.dimen.list_item_default_margin),
-                        SelectableListLayout.getDefaultListItemLateralShadowSizePx(
-                                parent.getResources()));
-            }
+    /**
+     * Initialize space display view in storage info header and generate header item for it.
+     */
+    void generateHeaderItems() {
+        mSpaceDisplay = new SpaceDisplay(null, this);
+        View view = mSpaceDisplay.getView();
+        registerAdapterDataObserver(mSpaceDisplay);
+        if (mUiConfig != null) {
+            MarginResizer.createAndAttach(view, mUiConfig,
+                    view.getResources().getDimensionPixelSize(R.dimen.list_item_default_margin),
+                    SelectableListLayout.getDefaultListItemLateralShadowSizePx(
+                            view.getResources()));
         }
-
-        mSpaceDisplay.onChanged();
-        return new BasicViewHolder(mSpaceDisplay.getView());
+        mSpaceDisplayHeaderItem = new HeaderItem(0, view);
     }
 
     /** Called when a new DownloadItem has been created by the native DownloadManager. */
@@ -598,7 +606,7 @@ public class DownloadHistoryAdapter extends DateDividedAdapter
 
         clear(false);
         if (!filteredTimedItems.isEmpty() && !mIsSearching && mShouldShowStorageInfoHeader) {
-            addHeader();
+            setHeaders(mSpaceDisplayHeaderItem);
         }
 
         loadItems(filteredTimedItems);

chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadManagerToolbar.java

@@ -24,12 +24,20 @@ import java.util.List;
 public class DownloadManagerToolbar extends SelectableListToolbar<DownloadHistoryItemWrapper>
         implements DownloadUiObserver {
     private Spinner mSpinner;
+    private DownloadManagerUi mManager;
 
     public DownloadManagerToolbar(Context context, AttributeSet attrs) {
         super(context, attrs);
         inflateMenu(R.menu.download_manager_menu);
     }
 
+    /**
+     * @param manager The {@link DownloadManagerUi} associated with this toolbar.
+     */
+    public void setManager(DownloadManagerUi manager) {
+        mManager = manager;
+    }
+
     /**
      * Initializes the spinner for the download filter.
      * @param adapter The adapter associated with the spinner.
@@ -95,6 +103,12 @@ public class DownloadManagerToolbar extends SelectableListToolbar<DownloadHistor
         mSpinner.setAdapter(null);
     }
 
+    @Override
+    protected void showNormalView() {
+        super.showNormalView();
+        mManager.updateInfoButtonVisibility();
+    }
+
     @Override
     public void showSearchView() {
         super.showSearchView();

chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadManagerUi.java

@@ -9,6 +9,7 @@ import android.content.ComponentName;
 import android.content.Intent;
 import android.os.AsyncTask;
 import android.support.graphics.drawable.VectorDrawableCompat;
+import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.Toolbar.OnMenuItemClickListener;
 import android.view.LayoutInflater;
@@ -200,6 +201,13 @@ public class DownloadManagerUi implements OnMenuItemClickListener, SearchDelegat
         // Prevent every progress update from causing a transition animation.
         mRecyclerView.getItemAnimator().setChangeDuration(0);
 
+        mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
+            @Override
+            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
+                updateInfoButtonVisibility();
+            }
+        });
+
         mFilterAdapter = new FilterAdapter();
         mFilterAdapter.initialize(this);
         addObserver(mFilterAdapter);
@@ -207,6 +215,7 @@ public class DownloadManagerUi implements OnMenuItemClickListener, SearchDelegat
         mToolbar = (DownloadManagerToolbar) mSelectableListLayout.initializeToolbar(
                 R.layout.download_manager_toolbar, mBackendProvider.getSelectionDelegate(), 0, null,
                 R.id.normal_menu_group, R.id.selection_mode_menu_group, null, this, true);
+        mToolbar.setManager(this);
         mToolbar.initializeFilterSpinner(mFilterAdapter);
         mToolbar.initializeSearchView(this, R.string.download_manager_search, R.id.search_menu_id);
         mToolbar.setInfoMenuItem(R.id.info_menu_id);
@@ -454,6 +463,23 @@ public class DownloadManagerUi implements OnMenuItemClickListener, SearchDelegat
         mSnackbarManager.dismissSnackbars(mUndoDeletionSnackbarController);
     }
 
+    /**
+     * @return True if info menu item should be shown on download toolbar, false otherwise.
+     */
+    boolean shouldShowInfoButton() {
+        return mHistoryAdapter.getItemCount() > 0 && !mToolbar.isSearching();
+    }
+
+    /**
+     * Update info button visibility based on whether info header is visible on download page.
+     */
+    void updateInfoButtonVisibility() {
+        LinearLayoutManager layoutManager = (LinearLayoutManager) mRecyclerView.getLayoutManager();
+        boolean infoHeaderIsVisible = layoutManager.findFirstVisibleItemPosition() == 0;
+        mToolbar.updateInfoMenuItem(infoHeaderIsVisible && shouldShowInfoButton(),
+                mHistoryAdapter.shouldShowStorageInfoHeader());
+    }
+
     @VisibleForTesting
     public SnackbarManager getSnackbarManagerForTesting() {
         return mSnackbarManager;

chrome/android/java/src/org/chromium/chrome/browser/download/ui/SpaceDisplay.java

@@ -15,6 +15,7 @@ import android.view.ViewGroup;
 import android.widget.TextView;
 
 import org.chromium.base.ApiCompatibilityUtils;
+import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
 import org.chromium.base.ObserverList;
 import org.chromium.base.VisibleForTesting;
@@ -114,7 +115,7 @@ public class SpaceDisplay extends RecyclerView.AdapterDataObserver {
 
     SpaceDisplay(final ViewGroup parent, DownloadHistoryAdapter historyAdapter) {
         mHistoryAdapter = historyAdapter;
-        mView = (ViewGroup) LayoutInflater.from(parent.getContext())
+        mView = LayoutInflater.from(ContextUtils.getApplicationContext())
                         .inflate(R.layout.download_manager_ui_space_widget, parent, false);
         mSpaceUsedByDownloadsTextView = (TextView) mView.findViewById(R.id.size_downloaded);
         mSpaceUsedByOtherAppsTextView = (TextView) mView.findViewById(R.id.size_other_apps);

chrome/android/java/src/org/chromium/chrome/browser/history/HistoryAdapter.java

@@ -14,7 +14,7 @@ import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.widget.Button;
-import android.widget.FrameLayout;
+import android.widget.Space;
 import android.widget.TextView;
 
 import org.chromium.base.VisibleForTesting;
@@ -53,22 +53,24 @@ public class HistoryAdapter extends DateDividedAdapter implements BrowsingHistor
     private final ArrayList<HistoryItemView> mItemViews;
     private RecyclerView mRecyclerView;
 
-    private ViewGroup mPrivacyDisclaimers;
     private TextView mSignedInNotSyncedTextView;
     private TextView mSignedInSyncedTextView;
     private TextView mOtherFormsOfBrowsingHistoryTextView;
+    private Space mPrivacyDisclaimerBottomSpace;
     private Button mClearBrowsingDataButton;
-    private FrameLayout mClearBrowsingDataButtonContainer;
+    private HeaderItem mPrivacyDisclaimerHeaderItem;
+    private HeaderItem mClearBrowsingDataButtonHeaderItem;
 
     private boolean mHasOtherFormsOfBrowsingData;
     private boolean mHasSyncedData;
-    private boolean mIsHeaderInflated;
     private boolean mIsDestroyed;
     private boolean mIsInitialized;
     private boolean mIsLoadingItems;
     private boolean mIsSearching;
     private boolean mHasMorePotentialItems;
     private boolean mClearOnNextQueryComplete;
+    private boolean mPrivacyDisclaimersVisible;
+    private boolean mClearBrowsingDataButtonVisible;
     private long mNextQueryEndTime;
     private String mQueryText = EMPTY_QUERY;
     private int mDefaultTextMargin;
@@ -194,6 +196,7 @@ public class HistoryAdapter extends DateDividedAdapter implements BrowsingHistor
         for (HistoryItemView itemView : mItemViews) {
             itemView.onSignInStateChange();
         }
+        initialize();
         updateClearBrowsingDataButtonVisibility();
         setPrivacyDisclaimerVisibility();
     }
@@ -252,7 +255,7 @@ public class HistoryAdapter extends DateDividedAdapter implements BrowsingHistor
 
         boolean wasInitialized = mIsInitialized;
         if (!mIsInitialized) {
-            if (items.size() > 0 && !mIsSearching) addHeader();
+            if (items.size() > 0 && !mIsSearching) setHeaders();
             mIsInitialized = true;
         }
 
@@ -298,28 +301,34 @@ public class HistoryAdapter extends DateDividedAdapter implements BrowsingHistor
     }
 
     @Override
-    protected BasicViewHolder createHeader(ViewGroup parent) {
-        ViewGroup v = (ViewGroup) LayoutInflater.from(parent.getContext()).inflate(
-                R.layout.history_header, parent, false);
-        Resources resources = v.getResources();
-        mIsHeaderInflated = true;
+    protected BasicViewHolder createFooter(ViewGroup parent) {
+        return new BasicViewHolder(
+                LayoutInflater.from(parent.getContext())
+                        .inflate(R.layout.indeterminate_progress_view, parent, false));
+    }
 
-        mClearBrowsingDataButton = (Button) v.findViewById(R.id.clear_browsing_data_button);
-        mClearBrowsingDataButton.setOnClickListener(new OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                mHistoryManager.openClearBrowsingDataPreference();
-            }
-        });
-        mClearBrowsingDataButtonContainer = (FrameLayout) mClearBrowsingDataButton.getParent();
-        MarginResizer.createAndAttach(mClearBrowsingDataButtonContainer,
+    @Override
+    protected DateViewHolder createDateViewHolder(ViewGroup parent) {
+        DateViewHolder viewHolder = super.createDateViewHolder(parent);
+        MarginResizer.createAndAttach(viewHolder.itemView,
                 mHistoryManager.getSelectableListLayout().getUiConfig(),
-                SelectableListLayout.getDefaultListItemLateralMarginPx(resources), 0);
-        updateClearBrowsingDataButtonVisibility();
-
-        mPrivacyDisclaimers = (ViewGroup) v.findViewById(R.id.privacy_disclaimers);
+                getDefaultTextMargin(parent.getResources()),
+                SelectableListLayout.getDefaultListItemLateralShadowSizePx(parent.getResources()));
+        return viewHolder;
+    }
 
-        mSignedInNotSyncedTextView = (TextView) v.findViewById(R.id.signed_in_not_synced);
+    /**
+     * Initialize clear browsing data and privacy disclaimer header views and generate header
+     * items for them.
+     */
+    void generateHeaderItems() {
+        ViewGroup privacyDisclaimers =
+                (ViewGroup) View.inflate(mHistoryManager.getSelectableListLayout().getContext(),
+                        R.layout.history_privacy_disclaimer_header, null);
+        Resources resources = privacyDisclaimers.getResources();
+
+        mSignedInNotSyncedTextView =
+                (TextView) privacyDisclaimers.findViewById(R.id.signed_in_not_synced);
         setPrivacyDisclaimerText(mSignedInNotSyncedTextView,
                 R.string.android_history_no_synced_results, LEARN_MORE_LINK);
         MarginResizer.createAndAttach(mSignedInNotSyncedTextView,
@@ -327,7 +336,7 @@ public class HistoryAdapter extends DateDividedAdapter implements BrowsingHistor
                 getDefaultTextMargin(resources),
                 SelectableListLayout.getDefaultListItemLateralShadowSizePx(resources));
 
-        mSignedInSyncedTextView = (TextView) v.findViewById(R.id.signed_in_synced);
+        mSignedInSyncedTextView = (TextView) privacyDisclaimers.findViewById(R.id.signed_in_synced);
         setPrivacyDisclaimerText(mSignedInSyncedTextView,
                 R.string.android_history_has_synced_results, LEARN_MORE_LINK);
         MarginResizer.createAndAttach(mSignedInSyncedTextView,
@@ -335,8 +344,8 @@ public class HistoryAdapter extends DateDividedAdapter implements BrowsingHistor
                 getDefaultTextMargin(resources),
                 SelectableListLayout.getDefaultListItemLateralShadowSizePx(resources));
 
-        mOtherFormsOfBrowsingHistoryTextView = (TextView) v.findViewById(
-                R.id.other_forms_of_browsing_history);
+        mOtherFormsOfBrowsingHistoryTextView =
+                (TextView) privacyDisclaimers.findViewById(R.id.other_forms_of_browsing_history);
         boolean flagEnabled = ChromeFeatureList.isEnabled(ChromeFeatureList.TABS_IN_CBD);
         int disclaimerTextId = flagEnabled ? R.string.android_history_other_forms_of_history_new
                                            : R.string.android_history_other_forms_of_history;
@@ -348,25 +357,39 @@ public class HistoryAdapter extends DateDividedAdapter implements BrowsingHistor
                 getDefaultTextMargin(resources),
                 SelectableListLayout.getDefaultListItemLateralShadowSizePx(resources));
 
-        setPrivacyDisclaimerVisibility();
+        mPrivacyDisclaimerBottomSpace =
+                (Space) privacyDisclaimers.findViewById(R.id.privacy_disclaimer_bottom_space);
 
-        return new BasicViewHolder(v);
-    }
+        ViewGroup clearBrowsingDataButtonContainer =
+                (ViewGroup) View.inflate(mHistoryManager.getSelectableListLayout().getContext(),
+                        R.layout.history_clear_browsing_data_header, null);
 
-    @Override
-    protected BasicViewHolder createFooter(ViewGroup parent) {
-        return new BasicViewHolder(LayoutInflater.from(parent.getContext()).inflate(
-                R.layout.indeterminate_progress_view, parent, false));
+        mClearBrowsingDataButton = (Button) clearBrowsingDataButtonContainer.findViewById(
+                R.id.clear_browsing_data_button);
+        mClearBrowsingDataButton.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                mHistoryManager.openClearBrowsingDataPreference();
+            }
+        });
+        MarginResizer.createAndAttach(clearBrowsingDataButtonContainer,
+                mHistoryManager.getSelectableListLayout().getUiConfig(),
+                SelectableListLayout.getDefaultListItemLateralMarginPx(resources), 0);
+
+        mPrivacyDisclaimerHeaderItem = new HeaderItem(0, privacyDisclaimers);
+        mClearBrowsingDataButtonHeaderItem = new HeaderItem(1, clearBrowsingDataButtonContainer);
+        updateClearBrowsingDataButtonVisibility();
+        setPrivacyDisclaimerVisibility();
     }
 
-    @Override
-    protected DateViewHolder createDateViewHolder(ViewGroup parent) {
-        DateViewHolder viewHolder = super.createDateViewHolder(parent);
-        MarginResizer.createAndAttach(viewHolder.itemView,
-                mHistoryManager.getSelectableListLayout().getUiConfig(),
-                getDefaultTextMargin(parent.getResources()),
-                SelectableListLayout.getDefaultListItemLateralShadowSizePx(parent.getResources()));
-        return viewHolder;
+    /**
+     * Pass header items to {@link #setHeaders(HeaderItem...)} as parameters.
+     */
+    private void setHeaders() {
+        ArrayList<HeaderItem> args = new ArrayList<>();
+        if (mPrivacyDisclaimersVisible) args.add(mPrivacyDisclaimerHeaderItem);
+        if (mClearBrowsingDataButtonVisible) args.add(mClearBrowsingDataButtonHeaderItem);
+        setHeaders(args.toArray(new HeaderItem[args.size()]));
     }
 
     private void setPrivacyDisclaimerText(TextView view, int stringId, final  String url) {
@@ -396,26 +419,29 @@ public class HistoryAdapter extends DateDividedAdapter implements BrowsingHistor
      * Set visibility for privacy disclaimer layout and views.
      */
     void setPrivacyDisclaimerVisibility() {
-        if (!mIsHeaderInflated) return;
-
-        boolean show = hasPrivacyDisclaimers() && mHistoryManager.shouldShowInfoHeaderIfAvailable();
         boolean isSignedIn = ChromeSigninController.get().isSignedIn();
+        boolean shouldShowPrivacyDisclaimers =
+                hasPrivacyDisclaimers() && mHistoryManager.shouldShowInfoHeaderIfAvailable();
         mSignedInNotSyncedTextView.setVisibility(
                 !mHasSyncedData && isSignedIn ? View.VISIBLE : View.GONE);
         mSignedInSyncedTextView.setVisibility(mHasSyncedData ? View.VISIBLE : View.GONE);
         mOtherFormsOfBrowsingHistoryTextView.setVisibility(
                 mHasOtherFormsOfBrowsingData ? View.VISIBLE : View.GONE);
-        mPrivacyDisclaimers.setVisibility(show ? View.VISIBLE : View.GONE);
+        // Prevent from refreshing the recycler view if header visibility is not changed.
+        if (mPrivacyDisclaimersVisible == shouldShowPrivacyDisclaimers) return;
+        mPrivacyDisclaimersVisible = shouldShowPrivacyDisclaimers;
+        if (mIsInitialized) setHeaders();
     }
 
     private void updateClearBrowsingDataButtonVisibility() {
         // If the history header is not showing (e.g. when there is no browsing history),
         // mClearBrowsingDataButton will be null.
         if (mClearBrowsingDataButton == null) return;
-
-        mClearBrowsingDataButtonContainer.setVisibility(
-                !PrefServiceBridge.getInstance().canDeleteBrowsingHistory() ? View.GONE :
-                    View.VISIBLE);
+        boolean shouldShowButton = PrefServiceBridge.getInstance().canDeleteBrowsingHistory();
+        if (mClearBrowsingDataButtonVisible == shouldShowButton) return;
+        mClearBrowsingDataButtonVisible = shouldShowButton;
+        mPrivacyDisclaimerBottomSpace.setVisibility(shouldShowButton ? View.GONE : View.VISIBLE);
+        if (mIsInitialized) setHeaders();
     }
 
     private int getDefaultTextMargin(Resources resources) {
@@ -441,12 +467,27 @@ public class HistoryAdapter extends DateDividedAdapter implements BrowsingHistor
     }
 
     @VisibleForTesting
-    ViewGroup getPrivacyDisclaimersForTests() {
-        return mPrivacyDisclaimers;
+    ItemGroup getFirstGroupForTests() {
+        return getGroupAt(0).first;
+    }
+
+    @VisibleForTesting
+    void setClearBrowsingDataButtonVisibilityForTest(boolean isVisible) {
+        if (mClearBrowsingDataButton == null) return;
+        if (mClearBrowsingDataButtonVisible == isVisible) return;
+        mClearBrowsingDataButtonVisible = isVisible;
+        if (mIsInitialized) setHeaders();
     }
 
     @VisibleForTesting
     public ArrayList<HistoryItemView> getItemViewsForTests() {
         return mItemViews;
     }
+
+    @VisibleForTesting
+    void generateHeaderItemsForTest() {
+        mPrivacyDisclaimerHeaderItem = new HeaderItem(0, null);
+        mClearBrowsingDataButtonHeaderItem = new HeaderItem(1, null);
+        mClearBrowsingDataButtonVisible = true;
+    }
 }

chrome/android/java/src/org/chromium/chrome/browser/history/HistoryManager.java

@@ -134,17 +134,23 @@ public class HistoryManager implements OnMenuItemClickListener, SignInStateObser
         mLargeIconBridge.createCache(maxSize);
 
         // 7. Initialize the adapter to load items.
+        mHistoryAdapter.generateHeaderItems();
         mHistoryAdapter.initialize();
 
-        // 8. Add scroll listener to page in more items when necessary.
+        // 8. Add scroll listener to show/hide info button on scroll and page in more items
+        // when necessary.
         mRecyclerView.addOnScrollListener(new OnScrollListener() {
             @Override
             public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
-                if (!mHistoryAdapter.canLoadMoreItems()) return;
-
-                // Load more items if the scroll position is close to the bottom of the list.
                 LinearLayoutManager layoutManager =
                         (LinearLayoutManager) recyclerView.getLayoutManager();
+                // Show info button if available if first visible position is close to info header;
+                // otherwise hide info button.
+                mToolbar.updateInfoMenuItem(infoHeaderIsVisible() && shouldShowInfoButton(),
+                        shouldShowInfoHeaderIfAvailable());
+
+                if (!mHistoryAdapter.canLoadMoreItems()) return;
+                // Load more items if the scroll position is close to the bottom of the list.
                 if (layoutManager.findLastVisibleItemPosition()
                         > (mHistoryAdapter.getItemCount() - 25)) {
                     mHistoryAdapter.loadMoreItems();
@@ -414,7 +420,8 @@ public class HistoryManager implements OnMenuItemClickListener, SignInStateObser
      * @return True if info menu item should be shown on history toolbar, false otherwise.
      */
     boolean shouldShowInfoButton() {
-        return mHistoryAdapter.hasPrivacyDisclaimers();
+        return mHistoryAdapter.hasPrivacyDisclaimers() && mHistoryAdapter.getItemCount() > 0
+                && !mToolbar.isSearching();
     }
 
     /**
@@ -425,6 +432,14 @@ public class HistoryManager implements OnMenuItemClickListener, SignInStateObser
         return mShouldShowInfoHeader;
     }
 
+    /**
+     * @return True if info header is visible on history page.
+     */
+    boolean infoHeaderIsVisible() {
+        LinearLayoutManager layoutManager = (LinearLayoutManager) mRecyclerView.getLayoutManager();
+        return (layoutManager.findFirstVisibleItemPosition() == 0);
+    }
+
     @Override
     public void onSignedIn() {
         mToolbar.onSignInStateChange();

chrome/android/java/src/org/chromium/chrome/browser/history/HistoryManagerToolbar.java

@@ -44,8 +44,8 @@ public class HistoryManagerToolbar extends SelectableListToolbar<HistoryItem> {
     @Override
     protected void showNormalView() {
         super.showNormalView();
-        updateInfoMenuItem(
-                mManager.shouldShowInfoButton(), mManager.shouldShowInfoHeaderIfAvailable());
+        updateInfoMenuItem(mManager.infoHeaderIsVisible() && mManager.shouldShowInfoButton(),
+                mManager.shouldShowInfoHeaderIfAvailable());
     }
 
     @Override
@@ -77,9 +77,7 @@ public class HistoryManagerToolbar extends SelectableListToolbar<HistoryItem> {
     @Override
     protected void onDataChanged(int numItems) {
         super.onDataChanged(numItems);
-        getMenu()
-                .findItem(R.id.info_menu_id)
-                .setVisible(mManager.shouldShowInfoButton() && !mIsSearching && numItems > 0);
+        getMenu().findItem(R.id.info_menu_id).setVisible(mManager.shouldShowInfoButton());
     }
 
     /**

chrome/android/java/src/org/chromium/chrome/browser/widget/DateDividedAdapter.java

@@ -105,6 +105,41 @@ public abstract class DateDividedAdapter extends Adapter<RecyclerView.ViewHolder
         public abstract long getStableId();
     }
 
+    /**
+     * Contains information of a single header that this adapter uses to manage headers.
+     */
+    public static class HeaderItem extends TimedItem {
+        private final long mStableId;
+        private final View mView;
+
+        /**
+         * Initialize stable id and view associated with this HeaderItem.
+         * @param position Position of this HeaderItem in the header group.
+         * @param view View associated with this HeaderItem.
+         */
+        public HeaderItem(int position, View view) {
+            mStableId = getTimestamp() - position;
+            mView = view;
+        }
+
+        @Override
+        public long getTimestamp() {
+            return Long.MAX_VALUE;
+        }
+
+        @Override
+        public long getStableId() {
+            return mStableId;
+        }
+
+        /**
+         * @return The View associated with this HeaderItem.
+         */
+        public View getView() {
+            return mView;
+        }
+    }
+
     /**
      * A {@link RecyclerView.ViewHolder} that displays a date header.
      */
@@ -193,6 +228,10 @@ public abstract class DateDividedAdapter extends Adapter<RecyclerView.ViewHolder
             mItems.remove(item);
         }
 
+        public void removeAllItems() {
+            mItems.clear();
+        }
+
         /** Records the position of all the TimedItems in this group, relative to the full list. */
         public void setPosition(int index) {
             assert mIndex == 0 || mIndex == TimedItem.INVALID_POSITION;
@@ -225,15 +264,18 @@ public abstract class DateDividedAdapter extends Adapter<RecyclerView.ViewHolder
          * @return The size of this group.
          */
         public int size() {
-            if (mIsListHeader || mIsListFooter) return 1;
+            if (mIsListHeader) return mItems.size();
+            if (mIsListFooter) return 1;
 
             // Plus 1 to account for the date header.
             return mItems.size() + 1;
         }
 
         public TimedItem getItemAt(int index) {
-            // 0 is allocated to the date header. The list header has no items.
-            if (index <= 0 || mIsListHeader || mIsListFooter) return null;
+            // 0 is allocated to the date header. Return item if list header has
+            // header items, otherwise return null.
+            if (mIsListHeader) return mItems.get(index);
+            if (index <= 0 || mIsListFooter) return null;
 
             sortIfNeeded();
             return mItems.get(index - 1);
@@ -305,12 +347,15 @@ public abstract class DateDividedAdapter extends Adapter<RecyclerView.ViewHolder
     protected abstract ViewHolder createViewHolder(ViewGroup parent);
 
     /**
-     * Creates a {@link BasicViewHolder} in the given view parent for the header.
+     * Creates a {@link BasicViewHolder} in the given view parent for the header. The default
+     * implementation will create an empty FrameLayout container as the view holder.
      * @see #onCreateViewHolder(ViewGroup, int)
      */
-    @Nullable
     protected BasicViewHolder createHeader(ViewGroup parent) {
-        return null;
+        // Create an empty layout as a container for the header view.
+        View v = LayoutInflater.from(parent.getContext())
+                         .inflate(R.layout.date_divided_adapter_header_view_holder, parent, false);
+        return new BasicViewHolder(v);
     }
 
     /**
@@ -362,6 +407,18 @@ public abstract class DateDividedAdapter extends Adapter<RecyclerView.ViewHolder
     protected void bindViewHolderForSubsectionHeader(
             SubsectionHeaderViewHolder holder, TimedItem timedItem) {}
 
+    /**
+     * Binds the {@link BasicViewHolder} with the given {@link HeaderItem}.
+     * @see #onBindViewHolder(ViewHolder, int)
+     */
+    protected void bindViewHolderForHeaderItem(ViewHolder viewHolder, HeaderItem headerItem) {
+        BasicViewHolder basicViewHolder = (BasicViewHolder) viewHolder;
+        View v = headerItem.getView();
+        ((ViewGroup) basicViewHolder.itemView).removeAllViews();
+        if (v.getParent() != null) ((ViewGroup) v.getParent()).removeView(v);
+        ((ViewGroup) basicViewHolder.itemView).addView(v);
+    }
+
     /**
      * Gets the resource id of the view showing the date header.
      * Contract for subclasses: this view should be a {@link TextView}.
@@ -420,17 +477,40 @@ public abstract class DateDividedAdapter extends Adapter<RecyclerView.ViewHolder
     }
 
     /**
-     * Adds a header as the first group in this adapter.
+     * Add a list of headers as the first group in this adapter. If headerItems has no items,
+     * the header group will not be created. Otherwise, header items will be added as child items
+     * to the header group. Note that any previously added header items will be removed.
+     * {@link #bindViewHolderForHeaderItem(ViewHolder, HeaderItem)} will bind the HeaderItem views
+     * to the given ViewHolder. Sub-classes may override #bindViewHolderForHeaderItem and
+     * (@link #createHeader(ViewGroup)} if custom behavior is needed.
+     *
+     * @param headerItems Zero or more header items to be add to the header item group.
      */
-    public void addHeader() {
-        assert mSize == 0;
+    public void setHeaders(HeaderItem... headerItems) {
+        if (headerItems == null || headerItems.length == 0) {
+            removeHeader();
+            return;
+        }
 
-        ItemGroup header = new ItemGroup(Long.MAX_VALUE);
-        header.mIsListHeader = true;
+        ItemGroup header;
+        if (mHasListHeader) {
+            header = mGroups.first();
+            mSize -= header.size();
+            header.removeAllItems();
+        } else {
+            header = new ItemGroup(Long.MAX_VALUE);
+            header.mIsListHeader = true;
+            mGroups.add(header);
+        }
 
-        mGroups.add(header);
-        mSize++;
+        for (HeaderItem item : headerItems) {
+            header.addItem(item);
+            mSize++;
+        }
         mHasListHeader = true;
+
+        setGroupPositions();
+        notifyDataSetChanged();
     }
 
     /**
@@ -439,8 +519,8 @@ public abstract class DateDividedAdapter extends Adapter<RecyclerView.ViewHolder
     public void removeHeader() {
         if (!mHasListHeader) return;
 
+        mSize -= mGroups.first().size();
         mGroups.remove(mGroups.first());
-        mSize--;
         mHasListHeader = false;
 
         setGroupPositions();
@@ -510,7 +590,8 @@ public abstract class DateDividedAdapter extends Adapter<RecyclerView.ViewHolder
     public Pair<Date, TimedItem> getItemAt(int position) {
         Pair<ItemGroup, Integer> pair = getGroupAt(position);
         ItemGroup group = pair.first;
-        return new Pair<>(group.mDate, group.getItemAt(pair.second));
+        return new Pair<>(group.mDate,
+                group.mIsListHeader ? group.getItemAt(position) : group.getItemAt(pair.second));
     }
 
     @Override
@@ -556,6 +637,8 @@ public abstract class DateDividedAdapter extends Adapter<RecyclerView.ViewHolder
             bindViewHolderForSubsectionHeader((SubsectionHeaderViewHolder) holder, pair.second);
         } else if (!(holder instanceof BasicViewHolder)) {
             bindViewHolderForTimedItem(holder, pair.second);
+        } else if (pair.second instanceof HeaderItem) {
+            bindViewHolderForHeaderItem(holder, (HeaderItem) pair.second);
         }
     }
 
@@ -569,7 +652,7 @@ public abstract class DateDividedAdapter extends Adapter<RecyclerView.ViewHolder
      */
     protected Pair<ItemGroup, Integer> getGroupAt(int position) {
         // TODO(ianwen): Optimize the performance if the number of groups becomes too large.
-        if (mHasListHeader && position == 0) {
+        if (mHasListHeader && position < mGroups.first().size()) {
             assert mGroups.first().mIsListHeader;
             return new Pair<>(mGroups.first(), TYPE_HEADER);
         }

chrome/android/javatests/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapterTest.java

@@ -90,7 +90,7 @@ public class DownloadHistoryAdapterTest {
         editor.putBoolean(PREF_SHOW_STORAGE_INFO_HEADER, true).apply();
     }
 
-    private void initializeAdapter(boolean showOffTheRecord) throws Exception {
+    private void initializeAdapter(boolean showOffTheRecord, boolean hasHeader) throws Exception {
         mObserver = new Observer();
         mAdapter = new DownloadHistoryAdapter(showOffTheRecord, null);
         mAdapter.registerAdapterDataObserver(mObserver);
@@ -106,14 +106,17 @@ public class DownloadHistoryAdapterTest {
             }
         });
         mDownloadDelegate.addCallback.waitForCallback(0);
-        mObserver.onChangedCallback.waitForCallback(callCount, 1);
+        // If header should be added, onChanged() will be called twice because both setHeaders()
+        // and loadMoreItems() will call notifyDataSetChanged(). Otherwise, setHeaders() will not
+        // be called and onChanged() will only be called once.
+        mObserver.onChangedCallback.waitForCallback(callCount, hasHeader ? 2 : 1);
     }
 
     /** Nothing downloaded, nothing shown. */
     @Test
     @SmallTest
     public void testInitialize_Empty() throws Exception {
-        initializeAdapter(false);
+        initializeAdapter(false, false);
         Assert.assertEquals(0, mAdapter.getItemCount());
         Assert.assertEquals(0, mAdapter.getTotalDownloadSize());
 
@@ -133,7 +136,7 @@ public class DownloadHistoryAdapterTest {
     public void testInitialize_SingleItem() throws Exception {
         DownloadItem item = StubbedProvider.createDownloadItem(0, "19840116 12:00");
         mDownloadDelegate.regularItems.add(item);
-        initializeAdapter(false);
+        initializeAdapter(false, true);
         checkAdapterContents(HEADER, null, item);
         Assert.assertEquals(1, mAdapter.getTotalDownloadSize());
     }
@@ -146,7 +149,7 @@ public class DownloadHistoryAdapterTest {
         DownloadItem item1 = StubbedProvider.createDownloadItem(1, "19840116 12:01");
         mDownloadDelegate.regularItems.add(item0);
         mDownloadDelegate.regularItems.add(item1);
-        initializeAdapter(false);
+        initializeAdapter(false, true);
         checkAdapterContents(HEADER, null, item1, item0);
         Assert.assertEquals(11, mAdapter.getTotalDownloadSize());
     }
@@ -159,7 +162,7 @@ public class DownloadHistoryAdapterTest {
         DownloadItem item1 = StubbedProvider.createDownloadItem(1, "19840117 12:00");
         mDownloadDelegate.regularItems.add(item0);
         mDownloadDelegate.regularItems.add(item1);
-        initializeAdapter(false);
+        initializeAdapter(false, true);
         checkAdapterContents(HEADER, null, item1, null, item0);
         Assert.assertEquals(11, mAdapter.getTotalDownloadSize());
     }
@@ -172,7 +175,7 @@ public class DownloadHistoryAdapterTest {
         editor.putBoolean(PREF_SHOW_STORAGE_INFO_HEADER, false).apply();
         DownloadItem item = StubbedProvider.createDownloadItem(0, "19840116 12:00");
         mDownloadDelegate.regularItems.add(item);
-        initializeAdapter(false);
+        initializeAdapter(false, false);
         checkAdapterContents(null, item);
         Assert.assertEquals(1, mAdapter.getTotalDownloadSize());
     }
@@ -185,7 +188,7 @@ public class DownloadHistoryAdapterTest {
         DownloadItem item1 = StubbedProvider.createDownloadItem(1, "19840116 12:01");
         mDownloadDelegate.regularItems.add(item0);
         mDownloadDelegate.regularItems.add(item1);
-        initializeAdapter(false);
+        initializeAdapter(false, true);
         checkAdapterContents(HEADER, null, item1, item0);
         Assert.assertEquals(11, mAdapter.getTotalDownloadSize());
 
@@ -216,7 +219,7 @@ public class DownloadHistoryAdapterTest {
         DownloadItem item1 = StubbedProvider.createDownloadItem(1, "19840116 12:01");
         mDownloadDelegate.regularItems.add(item0);
         mDownloadDelegate.offTheRecordItems.add(item1);
-        initializeAdapter(false);
+        initializeAdapter(false, true);
         checkAdapterContents(HEADER, null, item0);
         Assert.assertEquals(1, mAdapter.getTotalDownloadSize());
     }
@@ -229,7 +232,7 @@ public class DownloadHistoryAdapterTest {
         DownloadItem item1 = StubbedProvider.createDownloadItem(1, "19840116 12:00");
         mDownloadDelegate.regularItems.add(item0);
         mDownloadDelegate.offTheRecordItems.add(item1);
-        initializeAdapter(true);
+        initializeAdapter(true, true);
         checkAdapterContents(HEADER, null, item0, item1);
         Assert.assertEquals(11, mAdapter.getTotalDownloadSize());
     }
@@ -244,7 +247,7 @@ public class DownloadHistoryAdapterTest {
         mDownloadDelegate.regularItems.add(item0);
         mDownloadDelegate.offTheRecordItems.add(item1);
         mOfflineDelegate.items.add(item2);
-        initializeAdapter(true);
+        initializeAdapter(true, true);
         checkAdapterContents(HEADER, null, item2, null, item0, item1);
         Assert.assertEquals(100011, mAdapter.getTotalDownloadSize());
     }
@@ -254,7 +257,7 @@ public class DownloadHistoryAdapterTest {
     @SmallTest
     public void testUpdate_UpdateItems() throws Exception {
         // Start with an empty Adapter.
-        initializeAdapter(false);
+        initializeAdapter(false, false);
         Assert.assertEquals(0, mAdapter.getItemCount());
         Assert.assertEquals(0, mAdapter.getTotalDownloadSize());
 
@@ -267,7 +270,7 @@ public class DownloadHistoryAdapterTest {
         Assert.assertEquals(1, mAdapter.getTotalDownloadSize());
 
         // Add a second item with a different date.
-        Assert.assertEquals(2, mObserver.onChangedCallback.getCallCount());
+        Assert.assertEquals(3, mObserver.onChangedCallback.getCallCount());
         DownloadItem item1 = StubbedProvider.createDownloadItem(1, "19840117 12:00");
         mAdapter.onDownloadItemCreated(item1);
         mObserver.onChangedCallback.waitForCallback(2);
@@ -323,26 +326,28 @@ public class DownloadHistoryAdapterTest {
         mDownloadDelegate.regularItems.add(regularItem);
         mDownloadDelegate.offTheRecordItems.add(offTheRecordItem);
         mOfflineDelegate.items.add(offlineItem);
-        initializeAdapter(true);
+        initializeAdapter(true, true);
         checkAdapterContents(HEADER, null, offlineItem, null, regularItem, offTheRecordItem);
         Assert.assertEquals(100011, mAdapter.getTotalDownloadSize());
 
-        // Remove an item from the date bucket with two items.
-        Assert.assertEquals(1, mObserver.onChangedCallback.getCallCount());
+        // Remove an item from the date bucket with two items. Wait for two callbacks as
+        // notifyDataSetChanged() is called once when setHeaders() is called and once when items
+        // are loaded.
+        Assert.assertEquals(2, mObserver.onChangedCallback.getCallCount());
         mAdapter.onDownloadItemRemoved(offTheRecordItem.getId(), true);
         mObserver.onChangedCallback.waitForCallback(1);
         checkAdapterContents(HEADER, null, offlineItem, null, regularItem);
         Assert.assertEquals(100001, mAdapter.getTotalDownloadSize());
 
         // Remove an item from the second bucket, which removes the bucket entirely.
-        Assert.assertEquals(2, mObserver.onChangedCallback.getCallCount());
+        Assert.assertEquals(4, mObserver.onChangedCallback.getCallCount());
         mOfflineDelegate.observer.onItemDeleted(offlineItem.getGuid());
         mObserver.onChangedCallback.waitForCallback(2);
         checkAdapterContents(HEADER, null, regularItem);
         Assert.assertEquals(1, mAdapter.getTotalDownloadSize());
 
         // Remove the last item in the list.
-        Assert.assertEquals(3, mObserver.onChangedCallback.getCallCount());
+        Assert.assertEquals(6, mObserver.onChangedCallback.getCallCount());
         mAdapter.onDownloadItemRemoved(regularItem.getId(), false);
         mObserver.onChangedCallback.waitForCallback(3);
         Assert.assertEquals(0, mAdapter.getItemCount());
@@ -367,7 +372,7 @@ public class DownloadHistoryAdapterTest {
         mDownloadDelegate.offTheRecordItems.add(item4);
         mDownloadDelegate.regularItems.add(item5);
         mOfflineDelegate.items.add(item6);
-        initializeAdapter(true);
+        initializeAdapter(true, true);
         checkAdapterContents(
                 HEADER, null, item5, item4, item6, null, item3, item2, null, item1, item0);
         Assert.assertEquals(1666, mAdapter.getTotalDownloadSize());
@@ -401,7 +406,7 @@ public class DownloadHistoryAdapterTest {
         mOfflineDelegate.items.add(item0);
         mOfflineDelegate.items.add(item1);
         mOfflineDelegate.items.add(item2);
-        initializeAdapter(false);
+        initializeAdapter(false, true);
         checkAdapterContents(HEADER, null, item2, null, item1, item0);
         Assert.assertEquals(111000, mAdapter.getTotalDownloadSize());
 
@@ -427,7 +432,7 @@ public class DownloadHistoryAdapterTest {
     public void testInProgress_FilePathMapAccurate() throws Exception {
         Set<DownloadHistoryItemWrapper> toDelete;
 
-        initializeAdapter(false);
+        initializeAdapter(false, false);
         Assert.assertEquals(0, mAdapter.getItemCount());
         Assert.assertEquals(0, mAdapter.getTotalDownloadSize());
 
@@ -486,7 +491,7 @@ public class DownloadHistoryAdapterTest {
         mDownloadDelegate.offTheRecordItems.add(item4);
         mDownloadDelegate.regularItems.add(item5);
         mOfflineDelegate.items.add(item6);
-        initializeAdapter(true);
+        initializeAdapter(true, true);
         checkAdapterContents(
                 HEADER, null, item5, item4, item6, null, item3, item2, null, item1, item0);
 
@@ -540,7 +545,7 @@ public class DownloadHistoryAdapterTest {
         mDownloadDelegate.offTheRecordItems.add(item4);
         mDownloadDelegate.regularItems.add(item5);
         mOfflineDelegate.items.add(item6);
-        initializeAdapter(true);
+        initializeAdapter(true, true);
         checkAdapterContents(
                 HEADER, null, item5, item4, item6, null, item3, item2, null, item1, item0);
 
@@ -586,7 +591,7 @@ public class DownloadHistoryAdapterTest {
         mDownloadDelegate.offTheRecordItems.add(item4);
         mDownloadDelegate.regularItems.add(item5);
         mOfflineDelegate.items.add(item6);
-        initializeAdapter(true);
+        initializeAdapter(true, true);
         checkAdapterContents(
                 HEADER, null, item5, item4, item6, null, item3, item2, null, item1, item0);
 

chrome/android/javatests/src/org/chromium/chrome/browser/history/HistoryActivityTest.java

@@ -34,6 +34,7 @@ import org.chromium.chrome.browser.preferences.PrefServiceBridge;
 import org.chromium.chrome.browser.profiles.Profile;
 import org.chromium.chrome.browser.signin.SigninManager;
 import org.chromium.chrome.browser.signin.SigninManager.SignInStateObserver;
+import org.chromium.chrome.browser.widget.DateDividedAdapter;
 import org.chromium.chrome.browser.widget.TintedImageButton;
 import org.chromium.chrome.browser.widget.selection.SelectableItemView;
 import org.chromium.chrome.browser.widget.selection.SelectableItemViewHolder;
@@ -442,11 +443,10 @@ public class HistoryActivityTest extends BaseActivityInstrumentationTestCase<His
         // Not signed in
         ChromeSigninController signinController = ChromeSigninController.get();
         signinController.setSignedInAccountName(null);
-        assertEquals(false, infoMenuItem.isVisible());
-        assertEquals(View.GONE, mAdapter.getSignedInNotSyncedViewForTests().getVisibility());
-        assertEquals(View.GONE, mAdapter.getSignedInSyncedViewForTests().getVisibility());
-        assertEquals(
-                View.GONE, mAdapter.getOtherFormsOfBrowsingHistoryViewForTests().getVisibility());
+        assertFalse(infoMenuItem.isVisible());
+        DateDividedAdapter.ItemGroup headerGroup = mAdapter.getFirstGroupForTests();
+        assertTrue(mAdapter.hasListHeader());
+        assertEquals(1, headerGroup.size());
 
         // Signed in but not synced and history has items
         signinController.setSignedInAccountName("test@gmail.com");
@@ -457,22 +457,100 @@ public class HistoryActivityTest extends BaseActivityInstrumentationTestCase<His
                 toolbar.onSignInStateChange();
             }
         });
-        assertEquals(true, infoMenuItem.isVisible());
+        assertTrue(infoMenuItem.isVisible());
 
         // Signed in, synced, has other forms and has items
         // Privacy disclaimers should be shown by default
         setHasOtherFormsOfBrowsingData(true, true);
-        assertEquals(true, infoMenuItem.isVisible());
-        assertEquals(View.VISIBLE, mAdapter.getPrivacyDisclaimersForTests().getVisibility());
+        assertTrue(infoMenuItem.isVisible());
+        headerGroup = mAdapter.getFirstGroupForTests();
+        assertTrue(mAdapter.hasListHeader());
+        assertEquals(2, headerGroup.size());
 
-        // Toggle Info Menu Item
+        // Toggle Info Menu Item to off
         ThreadUtils.runOnUiThreadBlocking(new Runnable() {
             @Override
             public void run() {
                 mHistoryManager.onMenuItemClick(infoMenuItem);
             }
         });
-        assertEquals(View.GONE, mAdapter.getPrivacyDisclaimersForTests().getVisibility());
+        headerGroup = mAdapter.getFirstGroupForTests();
+        assertTrue(mAdapter.hasListHeader());
+        assertEquals(1, headerGroup.size());
+
+        // Toggle Info Menu Item to on
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                mHistoryManager.onMenuItemClick(infoMenuItem);
+            }
+        });
+        headerGroup = mAdapter.getFirstGroupForTests();
+        assertTrue(mAdapter.hasListHeader());
+        assertEquals(2, headerGroup.size());
+
+        signinController.setSignedInAccountName(null);
+    }
+
+    @SmallTest
+    public void testInfoHeaderInSearchMode() throws Exception {
+        final HistoryManagerToolbar toolbar = mHistoryManager.getToolbarForTests();
+        final MenuItem infoMenuItem = toolbar.getItemById(R.id.info_menu_id);
+
+        // Sign in
+        int callCount = mTestObserver.onSelectionCallback.getCallCount();
+        ChromeSigninController signinController = ChromeSigninController.get();
+        signinController.setSignedInAccountName("test@gmail.com");
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                toolbar.onSignInStateChange();
+                mAdapter.onSignInStateChange();
+            }
+        });
+        mTestObserver.onChangedCallback.waitForCallback(callCount, 1);
+        DateDividedAdapter.ItemGroup firstGroup = mAdapter.getFirstGroupForTests();
+        assertTrue(infoMenuItem.isVisible());
+        assertTrue(mAdapter.hasListHeader());
+        assertEquals(2, firstGroup.size());
+
+        // Enter search mode
+        callCount = mTestObserver.onSelectionCallback.getCallCount();
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                toolbar.getMenu().performIdentifierAction(R.id.search_menu_id, 0);
+            }
+        });
+
+        mTestObserver.onSelectionCallback.waitForCallback(callCount, 1);
+        firstGroup = mAdapter.getFirstGroupForTests();
+        assertFalse(infoMenuItem.isVisible());
+        // The first group should be the history item group from SetUp()
+        assertFalse(mAdapter.hasListHeader());
+        assertEquals(3, firstGroup.size());
+
+        signinController.setSignedInAccountName(null);
+    }
+
+    @SmallTest
+    public void testInvisibleHeader() throws Exception {
+        assertTrue(mAdapter.hasListHeader());
+
+        // Not sign in and set clear browsing data button to invisible
+        ChromeSigninController signinController = ChromeSigninController.get();
+        signinController.setSignedInAccountName(null);
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                mAdapter.setClearBrowsingDataButtonVisibilityForTest(false);
+                mAdapter.setPrivacyDisclaimerVisibility();
+            }
+        });
+
+        DateDividedAdapter.ItemGroup firstGroup = mAdapter.getFirstGroupForTests();
+        assertFalse(mAdapter.hasListHeader());
+        assertEquals(3, firstGroup.size());
     }
 
     @SmallTest

chrome/android/javatests/src/org/chromium/chrome/browser/history/HistoryAdapterTest.java

@@ -36,6 +36,7 @@ public class HistoryAdapterTest {
     public void setUp() throws Exception {
         mHistoryProvider = new StubbedHistoryProvider();
         mAdapter = new HistoryAdapter(new SelectionDelegate<HistoryItem>(), null, mHistoryProvider);
+        mAdapter.generateHeaderItemsForTest();
     }
 
     private void initializeAdapter() {