Fix UI style of signin AlertDialogs on Android

chrome/android/java/src/org/chromium/chrome/browser/signin/ConfirmSyncDataStateMachineDelegate.java

 // 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.
 
 package org.chromium.chrome.browser.signin;
 
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.support.v7.app.AlertDialog;
@@ skipping 42 matching lines @@
         mContext = context;
     }
 
     /**
      * Shows progress dialog. Will dismiss other dialogs shown, if any.
      *
      * @param listener The {@link ProgressDialogListener} that will be notified about user actions.
      */
     public void showFetchManagementPolicyProgressDialog(final ProgressDialogListener listener) {
         dismissAllDialogs();
-        mProgressDialog = new AlertDialog.Builder(mContext, R.style.AlertDialogTheme)
+        mProgressDialog = new AlertDialog.Builder(mContext, R.style.SigninAlertDialogTheme)
                                   .setView(R.layout.signin_progress_bar_dialog)
                                   .setNegativeButton(R.string.cancel,
                                           new DialogInterface.OnClickListener() {
                                               @Override
                                               public void onClick(DialogInterface dialog, int i) {
                                                   dialog.cancel();
                                               }
                                           })
                                   .setOnCancelListener(new DialogInterface.OnCancelListener() {
                                       @Override
                                       public void onCancel(DialogInterface dialog) {
                                           listener.onCancel();
                                       }
                                   })
                                   .create();
         mProgressDialog.show();
     }
 
     /**
      * Shows timeout dialog. Will dismiss other dialogs shown, if any.
      *
      * @param listener The {@link TimeoutDialogListener} that will be notified about user actions.
      */
     public void showFetchManagementPolicyTimeoutDialog(final TimeoutDialogListener listener) {
         dismissAllDialogs();
         mTimeoutAlertDialog =
-                new AlertDialog.Builder(mContext, R.style.AlertDialogTheme)
+                new AlertDialog.Builder(mContext, R.style.SigninAlertDialogTheme)
                         .setTitle(R.string.sign_in_timeout_title)
                         .setMessage(R.string.sign_in_timeout_message)
                         .setNegativeButton(R.string.cancel,
                                 new DialogInterface.OnClickListener() {
                                     @Override
                                     public void onClick(DialogInterface dialog, int which) {
                                         dialog.cancel();
                                     }
                                 })
                         .setPositiveButton(R.string.retry,
@@ skipping 17 matching lines @@
      * Dismisses all dialogs.
      */
     public void dismissAllDialogs() {
         if (mProgressDialog != null) mProgressDialog.dismiss();
         mProgressDialog = null;
 
         if (mTimeoutAlertDialog != null) mTimeoutAlertDialog.dismiss();
         mTimeoutAlertDialog = null;
     }
 }