[Android] Introduce DateDividedAdapter to Chrome

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

Index: chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java b/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java
index eb775170a9368160f5f342e1a2cadabf0e9d1602..217cc0868dfe099d964566b0572b10b630a62023 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java
@@ -6,6 +6,7 @@ package org.chromium.chrome.browser.download.ui;
 
 import android.content.Context;
 import android.support.v7.widget.RecyclerView;
+import android.support.v7.widget.RecyclerView.ViewHolder;
 import android.text.TextUtils;
 import android.text.format.Formatter;
 import android.view.LayoutInflater;
@@ -17,22 +18,21 @@ import android.widget.TextView;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.download.DownloadItem;
 import org.chromium.chrome.browser.util.UrlUtilities;
+import org.chromium.chrome.browser.widget.DateDividedAdapter;
 
-import java.util.ArrayList;
 import java.util.List;
 
 /** Bridges the user's download history and the UI used to display it. */
-public class DownloadHistoryAdapter
-        extends RecyclerView.Adapter<DownloadHistoryAdapter.ViewHolder> {
+public class DownloadHistoryAdapter extends DateDividedAdapter {
 
     /** Holds onto a View that displays information about a downloaded file. */
-    static class ViewHolder extends RecyclerView.ViewHolder {
+    static class ItemViewHolder extends RecyclerView.ViewHolder {
         public ImageView mIconView;
         public TextView mFilenameView;
         public TextView mHostnameView;
         public TextView mFilesizeView;
 
-        public ViewHolder(View itemView) {
+        public ItemViewHolder(View itemView) {
             super(itemView);
             mIconView = (ImageView) itemView.findViewById(R.id.icon_view);
             mFilenameView = (TextView) itemView.findViewById(R.id.filename_view);
@@ -53,27 +53,28 @@ public class DownloadHistoryAdapter
     private static final String MIMETYPE_IMAGE = "image";
     private static final String MIMETYPE_DOCUMENT = "text";
 
-    private final List<DownloadItem> mDownloadItems = new ArrayList<>();
-
     /** Called when the user's download history has been gathered into a List of DownloadItems. */
     public void onAllDownloadsRetrieved(List<DownloadItem> list) {
-        mDownloadItems.clear();
-        for (DownloadItem item : list) mDownloadItems.add(item);
-        notifyDataSetChanged();
+        loadItems(list);
     }
 
     @Override
-    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    protected int getTimedItemViewResId() {
+        return R.layout.download_date_view;
+    }
+
+    @Override
+    public ViewHolder createViewHolder(ViewGroup parent) {
         View v = LayoutInflater.from(parent.getContext()).inflate(
                 R.layout.download_item_view, parent, false);
-        return new ViewHolder(v);
+        return new ItemViewHolder(v);
     }
 
     @Override
-    public void onBindViewHolder(ViewHolder holder, int position) {
+    public void bindViewHolderForTimedItem(ViewHolder current, TimedItem timedItem) {
+        ItemViewHolder holder = (ItemViewHolder) current;
         Context context = holder.mFilesizeView.getContext();
-
-        DownloadItem item = mDownloadItems.get(position);
+        DownloadItem item = (DownloadItem) timedItem;
         holder.mFilenameView.setText(item.getDownloadInfo().getFileName());
         holder.mHostnameView.setText(
                 UrlUtilities.formatUrlForSecurityDisplay(item.getDownloadInfo().getUrl(), false));
@@ -105,16 +106,6 @@ public class DownloadHistoryAdapter
         holder.mIconView.setImageResource(iconResource);
     }
 
-    @Override
-    public int getItemCount() {
-        return mDownloadItems.size();
-    }
-
-    /** Clears out all of the downloads tracked by the Adapter. */
-    public void clear() {
-        mDownloadItems.clear();
-    }
-
     /** Identifies the type of file represented by the given MIME type string. */
     private static int convertMimeTypeToFileType(String mimeType) {
         if (TextUtils.isEmpty(mimeType)) return FILETYPE_OTHER;