General comment cleaning / refactoring for Mac Installer

chrome/installer/mac/app/Unpacker.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 "Unpacker.h"
 
 #import <AppKit/AppKit.h>
 #include <DiskArbitration/DiskArbitration.h>
 #include <dispatch/dispatch.h>
 
@@ skipping 31 matching lines @@
 }
 
 @implementation Unpacker
 
 @synthesize delegate = delegate_;
 @synthesize appPath = appPath_;
 
 - (void)cleanUp {
   [mountTask_ terminate];
   // It's not the end of the world if this temporary directory is not removed
-  // here. It will be deleted when the operating system itself decides to
-  // anyway.
+  // here. The directory will be deleted when the operating system itself
+  // decides to anyway.
   [[NSFileManager defaultManager] removeItemAtURL:temporaryDirectoryURL_
                                             error:nil];
   [[NSNotificationCenter defaultCenter] removeObserver:self];
 }
 
-// TODO: the failure delegate methods need to be revised to be more meaningfully
-// deal with the errors (pipe in stderr / stdout)
+// TODO: The failure delegate methods need to be revised to meaningfully deal
+// with the errors (pipe in stderr / stdout to handle the error according to
+// what the error was).
 - (void)mountDMGFromURL:(NSURL*)fileURL {
   NSError* error = nil;
   temporaryDirectoryURL_ = [[NSFileManager defaultManager]
         URLForDirectory:NSItemReplacementDirectory
                inDomain:NSUserDomainMask
       appropriateForURL:[NSURL fileURLWithPath:@"/" isDirectory:YES]
                  create:YES
                   error:&error];
   if (error) {
     [delegate_ unpacker:self onMountFailure:error];
@@ skipping 87 matching lines @@
                      (__bridge NSString*)DADissenterGetStatusString(dissenter)
                }];
     [delegate_ unpacker:self onUnmountFailure:error];
   } else {
     [self cleanUp];
     [delegate_ unpacker:self onUnmountSuccess:mountPath_];
   }
 }
 
 @end