Created the dialog offering the user to merge their account data or keep it

chrome/android/java/src/org/chromium/chrome/browser/sync/ui/ConfirmImportSyncDataFragment.java

Index: chrome/android/java/src/org/chromium/chrome/browser/sync/ui/ConfirmImportSyncDataFragment.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/sync/ui/ConfirmImportSyncDataFragment.java b/chrome/android/java/src/org/chromium/chrome/browser/sync/ui/ConfirmImportSyncDataFragment.java
new file mode 100644
index 0000000000000000000000000000000000000000..75cdafe2cbd9e2ffb9e26d1e75d7bfdf67135915
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/sync/ui/ConfirmImportSyncDataFragment.java
@@ -0,0 +1,188 @@
+// Copyright 2016 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.sync.ui;
+
+import android.app.AlertDialog;
+import android.app.Dialog;
+import android.app.DialogFragment;
+import android.app.FragmentManager;
+import android.content.DialogInterface;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.widget.TextView;
+
+import org.chromium.base.metrics.RecordUserAction;
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.BrowsingDataType;
+import org.chromium.chrome.browser.preferences.PrefServiceBridge;
+import org.chromium.chrome.browser.preferences.PrefServiceBridge.OnClearBrowsingDataListener;
+import org.chromium.chrome.browser.provider.ChromeBrowserProviderClient;
+import org.chromium.chrome.browser.widget.RadioButtonWithDescription;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * A dialog that is displayed when the user switches the account they are syncing to. It gives the
+ * option to merge the data of the two accounts or to keep them separate.
+ */
+public class ConfirmImportSyncDataFragment extends DialogFragment

[newt (away), 2016/02/25 06:25:53]

suggestion: I think "ConfirmImportSyncDataDialog" is a more helpful name than
"ConfirmImportSyncDataFragment" (although both are accurate in some sense).

[PEConn, 2016/02/25 14:19:52]

Done.

+        implements DialogInterface.OnClickListener, OnClearBrowsingDataListener {
+
+    /**
+     * Callback for completion of the dialog.
+     */
+    public interface Listener {
+        /**
+         * The user has completed the dialog using the positive button. If requested, the previous
+         * sync data has been cleared.
+         */
+        public void onConfirm();
+    }
+
+    /**
+     * The situation ConfirmImportSyncDataFragment is created for - whether the user had previously
+     * been signed into another account, had signed out then signed into a different one, or
+     * if they directly switched accounts. This changes the strings displayed.
+     */
+    public enum ImportSyncType { SWITCHING_SYNC_ACCOUNTS, PREVIOUS_DATA_FOUND }
+
+    private static final String CONFIRM_IMPORT_SYNC_DATA_DIALOG_TAG =
+            "sync_account_switch_import_data_tag";
+
+    private static final int[] SYNC_DATA_TYPES = {
+            BrowsingDataType.HISTORY,
+            BrowsingDataType.CACHE,
+            BrowsingDataType.COOKIES,
+            BrowsingDataType.PASSWORDS,
+            BrowsingDataType.FORM_DATA
+    };
+
+    private static final String KEY_OLD_ACCOUNT_NAME = "lastAccountName";
+    private static final String KEY_NEW_ACCOUNT_NAME = "newAccountName";
+    private static final String KEY_IMPORT_SYNC_TYPE = "importSyncType";
+
+    private RadioButtonWithDescription mConfirmImportOption;
+    private RadioButtonWithDescription mKeepSeparateOption;
+
+    private Listener mListener;
+
+    private static ConfirmImportSyncDataFragment newInstance(
+            String oldAccountName, String newAccountName, ImportSyncType importSyncType) {
+
+        ConfirmImportSyncDataFragment fragment = new ConfirmImportSyncDataFragment();
+        Bundle args = new Bundle();
+        args.putString(KEY_OLD_ACCOUNT_NAME, oldAccountName);
+        args.putString(KEY_NEW_ACCOUNT_NAME, newAccountName);
+        args.putSerializable(KEY_IMPORT_SYNC_TYPE, importSyncType);
+        fragment.setArguments(args);
+        return fragment;
+    }
+
+    /**
+     * Creates and shows a new instance of ConfirmImportSyncDataFragment, a dialog that gives the
+     * user the option to merge data between the account they are attempting to sign in to and the
+     * account they were previously signed into, or to keep the data separate.
+     * @param oldAccountName  The previous sync account name.
+     * @param newAccountName  The potential next sync account name.
+     * @param importSyncType  The situation the dialog is created in - either when directly changing
+     *                        the sync account or signing in after being signed out (this changes
+     *                        displayed strings).
+     * @param fragmentManager FragmentManager to attach the dialog to.
+     * @param callback        Callback to be called if the user completes the dialog (as opposed to
+     *                        hitting cancel).
+     */
+    public static void showNewInstance(String oldAccountName, String newAccountName,
+            ImportSyncType importSyncType, FragmentManager fragmentManager, Listener callback) {
+        ConfirmImportSyncDataFragment confirmSync = ConfirmImportSyncDataFragment.newInstance(
+                oldAccountName, newAccountName, importSyncType);
+
+        confirmSync.setListener(callback);
+        confirmSync.show(fragmentManager, CONFIRM_IMPORT_SYNC_DATA_DIALOG_TAG);
+    }
+
+    @Override
+    public Dialog onCreateDialog(Bundle savedInstanceState) {
+        String oldAccountName = getArguments().getString(KEY_OLD_ACCOUNT_NAME);
+        String newAccountName = getArguments().getString(KEY_NEW_ACCOUNT_NAME);
+        ImportSyncType importSyncType =
+                (ImportSyncType) getArguments().getSerializable(KEY_IMPORT_SYNC_TYPE);
+
+        LayoutInflater inflater = getActivity().getLayoutInflater();
+        View v = inflater.inflate(R.layout.confirm_import_sync_data, null);
+
+        TextView prompt = (TextView) v.findViewById(R.id.sync_import_data_prompt);
+
+        if (importSyncType == ImportSyncType.SWITCHING_SYNC_ACCOUNTS) {
+            prompt.setText(getActivity().getString(
+                    R.string.sync_import_data_prompt_switching_accounts,
+                    newAccountName, oldAccountName));
+        } else {
+            prompt.setText(getActivity().getString(
+                    R.string.sync_import_data_prompt_existing_data,
+                    newAccountName, oldAccountName));
+        }
+
+        mConfirmImportOption = (RadioButtonWithDescription)
+                v.findViewById(R.id.sync_confirm_import_choice);
+        mKeepSeparateOption = (RadioButtonWithDescription)
+                v.findViewById(R.id.sync_keep_separate_choice);
+
+        mConfirmImportOption.setDescriptionText(getActivity().getString(
+                R.string.sync_import_existing_data_subtext, newAccountName));
+        mKeepSeparateOption.setDescriptionText(getActivity().getString(
+                R.string.sync_keep_existing_data_separate_subtext, newAccountName, oldAccountName));
+
+        List<RadioButtonWithDescription> radioGroup =
+                Arrays.asList(mConfirmImportOption, mKeepSeparateOption);
+        mConfirmImportOption.setRadioButtonGroup(radioGroup);
+        mKeepSeparateOption.setRadioButtonGroup(radioGroup);
+
+        if (importSyncType == ImportSyncType.SWITCHING_SYNC_ACCOUNTS) {
+            mKeepSeparateOption.setChecked(true);
+        } else {
+            mConfirmImportOption.setChecked(true);
+        }
+
+        return new AlertDialog.Builder(getActivity(), R.style.AlertDialogTheme)
+                .setTitle(getActivity().getString(R.string.sync_import_data_title))

[newt (away), 2016/02/25 06:25:53]

setTitle(), etc have overrides that take a string resource ID: 

    .setTitle(R.string.sync_import_data_title)
    .setPositiveButton(R.string.cont, this)
    etc

[PEConn, 2016/02/25 14:19:52]

Done.

+                .setPositiveButton(getActivity().getString(R.string.cont), this)
+                .setNegativeButton(getActivity().getString(R.string.cancel), this)
+                .setView(v)
+                .create();
+    }
+
+    private void setListener(Listener listener) {
+        assert mListener == null;
+        mListener = listener;
+    }
+
+    @Override
+    public void onClick(DialogInterface dialog, int which) {
+        if (which != AlertDialog.BUTTON_POSITIVE) {
+            RecordUserAction.record("Signin_ImportDataPrompt_Cancel");
+            return;
+        }
+        if (mListener == null) return;
+
+        assert mConfirmImportOption.isChecked() ^ mKeepSeparateOption.isChecked();
+
+        if (mConfirmImportOption.isChecked()) {
+            RecordUserAction.record("Signin_ImportDataPrompt_ImportData");
+            mListener.onConfirm();
+        } else {
+            RecordUserAction.record("Signin_ImportDataPrompt_DontImport");
+            ChromeBrowserProviderClient.removeAllUserBookmarks(getActivity());

[newt (away), 2016/02/25 06:25:53]

Does calling this on the UI thread work?

I'm just wondering because of all the complexity in
ClearSyncDataPreferences.java when calling this same method:
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/android/jav...

(In the nearish future, ChromeBrowserProviderClient.removeAllUserBookmarks()
will be replaced with a method that definitely does work on the UI thread, via
BookmarkBridge.)

[PEConn, 2016/02/25 14:19:52]

Done.

+            PrefServiceBridge.getInstance().clearBrowsingData(this, SYNC_DATA_TYPES);
+        }
+    }
+
+    @Override
+    public void onBrowsingDataCleared() {
+        mListener.onConfirm();
+    }
+}
+