[Android] Add enhanced bookmarks grid/list view experiment.

chrome/android/java_staging/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.enhancedbookmarks;
 
 import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.ActivityOptions;
 import android.content.Intent;
 import android.os.Build;
 import android.preference.PreferenceManager;
 import android.support.v4.widget.DrawerLayout;
 import android.util.Log;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ViewSwitcher;
 
 import com.google.android.apps.chrome.R;
 
 import org.chromium.base.ObserverList;
 import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.chrome.browser.BookmarksBridge.BookmarkItem;
 import org.chromium.chrome.browser.BookmarksBridge.BookmarkModelObserver;
 import org.chromium.chrome.browser.UrlConstants;
+import org.chromium.chrome.browser.enhanced_bookmarks.EnhancedBookmarksBridge;
 import org.chromium.chrome.browser.enhanced_bookmarks.EnhancedBookmarksBridge.FiltersObserver;
 import org.chromium.chrome.browser.enhanced_bookmarks.EnhancedBookmarksModel;
 import org.chromium.chrome.browser.enhanced_bookmarks.LaunchLocation;
+import org.chromium.chrome.browser.enhanced_bookmarks.ViewMode;
 import org.chromium.chrome.browser.ntp.NewTabPageUma;
 import org.chromium.chrome.browser.partnerbookmarks.PartnerBookmarksShim;
 import org.chromium.chrome.browser.snackbar.SnackbarManager.SnackbarManageable;
 import org.chromium.components.bookmarks.BookmarkId;
 import org.chromium.ui.base.DeviceFormFactor;
 
 import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 import java.net.URLEncoder;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.Stack;
 
 /**
  * The new bookmark manager that is planned to replace the existing bookmark manager. It holds all
  * views and shared logics between tablet and phone. For tablet/phone specific logics, see
  * {@link EnhancedBookmarkActivity} (phone) and {@link EnhancedBookmarkPage} (tablet).
  */
 public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
     private static final String PREF_LAST_USED_URL = "enhanced_bookmark_last_used_url";
     static final String PREF_WAS_IN_LIST_MODE = "enhanced_bookmark_list_mode_choice";
-    // TODO(ianwen): upstream these metrics upstream.
-    // UI modes for bookmarks presentation. Default option is grid mode.
-    static final int DEFAULT_MODE = 0;
-    static final int LIST_MODE = 1;
-    static final int GRID_MODE = 2;
 
     private Activity mActivity;
     private ViewGroup mMainView;
     private EnhancedBookmarksModel mEnhancedBookmarksModel;
     private EnhancedBookmarkUndoController mUndoController;
     private final ObserverList<EnhancedBookmarkUIObserver> mUIObservers =
             new ObserverList<EnhancedBookmarkUIObserver>();
     private Set<BookmarkId> mSelectedBookmarks = new HashSet<>();
     private boolean mListModeEnabled;
     private EnhancedBookmarkStateChangeListener mUrlChangeListener;
@@ skipping 214 matching lines @@
      * Fetches url to preference. Note this method should be used after the main view is attached to
      * an activity.
      */
     private String getUrlFromPreference() {
         return PreferenceManager.getDefaultSharedPreferences(mActivity).getString(
                 PREF_LAST_USED_URL, UrlConstants.BOOKMARKS_URL);
     }
 
     private void saveListModePreference() {
         PreferenceManager.getDefaultSharedPreferences(mActivity).edit()
-                .putInt(PREF_WAS_IN_LIST_MODE, mListModeEnabled ? LIST_MODE : GRID_MODE).apply();
+                .putInt(PREF_WAS_IN_LIST_MODE, mListModeEnabled ? ViewMode.LIST : ViewMode.GRID)
+                .apply();
     }
 
     private boolean getListModePreference() {
         int mode = PreferenceManager.getDefaultSharedPreferences(mActivity).getInt(
-                PREF_WAS_IN_LIST_MODE, DEFAULT_MODE);
-        return mode == LIST_MODE ? true : false;
+                PREF_WAS_IN_LIST_MODE, ViewMode.DEFAULT);
+
+        if (mode == ViewMode.DEFAULT) mode = EnhancedBookmarksBridge.getDefaultViewMode();
+
+        return mode == ViewMode.LIST ? true : false;
     }
 
     private void initListModeOptionTo(boolean isListModeEnabled) {
         mListModeEnabled = isListModeEnabled;
         for (EnhancedBookmarkUIObserver observer: mUIObservers) {
             observer.onListModeChange(isListModeEnabled);
         }
         // Every time the enhanced bookmark manager launches or the user clicks the list-mode
         // toggle, we record the list view state.
         int listViewstate = PreferenceManager.getDefaultSharedPreferences(getView().getContext())
                 .getInt(EnhancedBookmarkManager.PREF_WAS_IN_LIST_MODE,
-                        EnhancedBookmarkManager.DEFAULT_MODE);
+                        ViewMode.DEFAULT);
         RecordHistogram.recordEnumeratedHistogram("EnhancedBookmarks.ViewMode", listViewstate, 3);
     }
 
     /**
      * This is the ultimate internal method that updates UI and controls backstack. And it is the
      * only method that pushes states to {@link #mStateStack}.
      * <p>
      * If the given state is not valid, all_bookmark state will be shown. Afterwards, this method
      * checks the current state: if currently in loading state, it pops it out and adds the new
      * state to the back stack. It also notifies the {@link #mUrlChangeListener} (if any) that the
@@ skipping 318 matching lines @@
         }
 
         @Override
         public boolean equals(Object obj) {
             if (!(obj instanceof UIState)) return false;
             UIState other = (UIState) obj;
             return mState == other.mState && mUrl.equals(other.mUrl);
         }
     }
 }