General comment cleaning / refactoring for Mac Installer

chrome/installer/mac/app/Downloader.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 "Downloader.h"
 
 #include <assert.h>
 
 @implementation Downloader
 
@@ skipping 15 matching lines @@
 - (void)URLSession:(NSURLSession*)session
                  downloadTask:(NSURLSessionDownloadTask*)downloadTask
                  didWriteData:(int64_t)bytesWritten
             totalBytesWritten:(int64_t)totalBytesWritten
     totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite {
   double downloadProgressPercentage =
       (double)totalBytesWritten / totalBytesExpectedToWrite * 100.0;
   [delegate_ downloader:self percentProgress:downloadProgressPercentage];
 }
 
-// Delegate method to move downloaded disk image to user's Download directory.
 - (void)URLSession:(NSURLSession*)session
                  downloadTask:(NSURLSessionDownloadTask*)downloadTask
     didFinishDownloadingToURL:(NSURL*)location {
   assert([location isFileURL]);
   [delegate_ downloader:self onSuccess:location];
 }
 
 - (void)URLSession:(NSURLSession*)session
                     task:(NSURLSessionTask*)task
     didCompleteWithError:(NSError*)error {
   if (error) {
     [delegate_ downloader:self onFailure:error];
   }
 }
 
 @end