Added unpacking step

chrome/installer/mac/app/NSError+ChromeInstallerAdditions.m

 // 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.
 
 #import "NSError+ChromeInstallerAdditions.h"
 
 @implementation NSError (ChromeInstallerAdditions)
-// Creates a custom error object to be used as the popup alert that the user
-// will be shown.
 + (NSError*)errorForAlerts:(NSString*)message
            withDescription:(NSString*)description
              isRecoverable:(BOOL)recoverable {
   NSArray* options = @[];
   if (recoverable) {
     options = @[ @"Try Again", @"Quit" ];
   } else {
     options = @[ @"Quit" ];
   }
 
   NSDictionary* errorContents = @{
     NSLocalizedDescriptionKey : NSLocalizedString(message, nil),
     NSLocalizedRecoveryOptionsErrorKey : options,
     NSLocalizedRecoverySuggestionErrorKey : NSLocalizedString(description, nil)
   };
   return [NSError errorWithDomain:@"ChromeErrorDomain"
                              code:-1
                          userInfo:errorContents];
 }
 @end