Added unpacking step

chrome/installer/mac/app/OmahaXMLParser.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 "OmahaXMLParser.h"
 
 @interface OmahaXMLParser ()<NSXMLParserDelegate>
 @end
 
 @implementation OmahaXMLParser {
   NSMutableArray* chromeIncompleteDownloadURLs_;
   NSString* chromeImageFilename_;
 }
 
 // Sets up instance of NSXMLParser and calls on delegate methods to do actual
 // parsing work.
 + (NSArray*)parseXML:(NSData*)omahaResponseXML error:(NSError**)error {
   NSXMLParser* parser = [[NSXMLParser alloc] initWithData:omahaResponseXML];
 
   OmahaXMLParser* omahaParser = [[OmahaXMLParser alloc] init];
   [parser setDelegate:omahaParser];
   if (![parser parse]) {
     *error = [parser parserError];
-    // TODO: pass up error object to indicate error occurred so
-    // InstallerWindowController can create custom user error message.
     return nil;
   }
 
   NSMutableArray* completeDownloadURLs = [[NSMutableArray alloc] init];
   for (NSString* URL in omahaParser->chromeIncompleteDownloadURLs_) {
     [completeDownloadURLs
         addObject:[NSURL URLWithString:omahaParser->chromeImageFilename_
                          relativeToURL:[NSURL URLWithString:URL]]];
   }
 
   if ([completeDownloadURLs count] < 1) {
+    // TODO: currently whatever error is passed in doesn't matter... we should
+    // make it so that the type of error informs what the installer will do
+    // about the error
     *error = [NSError errorWithDomain:@"ChromeErrorDomain" code:1 userInfo:nil];
     return nil;
   }
 
   return completeDownloadURLs;
 }
 
 // Method implementation for XMLParserDelegate.
 // Searches the XML data for the tag "URL" and the subsequent "codebase"
 // attribute that indicates a URL follows. Copies each URL into an array.
@@ skipping 21 matching lines @@
 // If either component of the URL is empty then the complete URL cannot
 // be generated so both variables are set to nil to flag errors.
 - (void)parserDidEndDocument:(NSXMLParser*)parser {
   if (!chromeIncompleteDownloadURLs_ || !chromeImageFilename_) {
     chromeIncompleteDownloadURLs_ = nil;
     chromeImageFilename_ = nil;
   }
 }
 
 @end