General comment cleaning / refactoring for Mac Installer

chrome/installer/mac/app/copy_to_disk.sh

 #!/bin/sh -p
 
 # 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.
 
 # This script will be called by the installer application to copy Google
 # Chrome.app into the proper /Applications folder. This script may run as root.
 #
 # When running as root, this script will be invoked with the real user ID set
 # to the user's ID, but the effective user ID set to 0 (root).  bash -p is
 # used on the first line to prevent bash from setting the effective user ID to
 # the real user ID (dropping root privileges).
 
-# The 'e' flag causes the script to terminate if it comes across an error while
-# running. The 'u' flag will raise an error if a variable isn't set.
-# 'u pipefail' will set the return exit code to the last non-zero  error code.
+# 'e': terminate if error arises
+# 'u': raise an error if a variable isn't set
+# 'o pipefail': set the return exit code to the last non-zero error code
 set -euo pipefail
 
 # Waits for the main app to pass the path to the app bundle inside the mounted
 # disk image.
 read -r SRC
 
 DEST="${1}"
 APPBUNDLENAME=$(basename "${SRC}")
 FULL_DEST="${DEST}"/"${APPBUNDLENAME}"
 
 # Starts the copy
-# The 'l' flag tells rsync to copy symlinks as symlinks. 'r' is for recursive,
-# so copy all files, 'p' is to preserve permisisons. 't' is to preserve times.
-# 'q' is for quiet mode so rynsc will only log to console if an error occurs.
+# 'l': copy symlinks as symlinks
+# 'r': recursive copy
+# 'p': preserve permissions
+# 't': preserve times
+# 'q': quiet mode, so rynsc will only log to console if an error occurs

[Sidney San Martín, 2016/08/31 21:20:16]

I really like these comments which describe each flag :).

 rsync -lrptq "${SRC}" "${DEST}"
 
 # If this script is run as root, change ownership to root and set elevated
 # permissions.
 if [ "${EUID}" -eq 0 ] ; then
   chown -Rh root:admin "${FULL_DEST}"
   chmod -R a+rX,ug+w,o-w  "${FULL_DEST}"
 fi
 
 exit 0