Enable Touch Screen for Google Chrome in Ubuntu 14.10

My lappy, the Samsung 915S3G (see result below) which has touch screen support since the first day I've bought but never bother about it until today.
$ sudo dmidecode | grep "System Information" -A 3
System Information
    Manufacturer: SAMSUNG ELECTRONICS CO., LTD.
    Product Name: 905S3G/906S3G/915S3G
    Version: P03RBV

Since I've been reading a lot of PDF files and the keyboard of this lappy is just atrocious, is best to enable and calibrate touch screen support to obtain the best usage experience.

First, let's install the calibration program to detect your device manufacture name. This will be useful later when you want to set the default input device to Google Chrome.
$ sudo apt-get install xinput-calibrator

Run the calibration program, touch four points on your screen to calibrate your device, and save the result. As shown below, our touch screen device name is "ELAN Touchscreen" with id of 12.
$ xinput_calibrator 
        Setting calibration data: 0, 3776, 0, 2112
Calibrating EVDEV driver for "ELAN Touchscreen" id=12
        current calibration values (from XInput): min_x=0, max_x=3776 and min_y=0, max_y=2112

Doing dynamic recalibration:
        Setting calibration data: -15, 3795, 1, 2118
        --> Making the calibration permanent <--
  copy the snippet below into '/etc/X11/xorg.conf.d/99-calibration.conf' (/usr/share/X11/xorg.conf.d/ in some distro's)
Section "InputClass"
        Identifier      "calibration"
        MatchProduct    "ELAN Touchscreen"
        Option  "Calibration"   "-15 3795 1 2118"
        Option  "SwapAxes"      "0"
EndSection

Alternatively, we can find the device id of our touch screen device using the xinput command below. The device id we need is 12.
$ xinput list
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ ETPS/2 Elantech Touchpad                  id=11   [slave  pointer  (2)]
⎜   ↳ ELAN Touchscreen                          id=12   [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Power Button                              id=8    [slave  keyboard (3)]
    ↳ WebCam SC-10HDD13335N                     id=9    [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=10   [slave  keyboard (3)]

Lastly, we'll start Google Chrome browser by setting the input device id found above.
$ google-chrome --touch-devices=12

Resetting File or Folder Permissions Using Yum

While setting the group file or folder permissions and ownership to /var/www, sometimes we may accidentally update the wrong folder, like to the parent folder of /var instead of /var/www.

In order to restore the default file or folders permissions in RPM-based system, there is a built-in option to revert the changes quickly compare to DEB-based system. Yup, this is probably one of the missing feature if we compare both packaging system.

First, let's find the RPM package name that contains the /var/www/html folder.

Using the rpm command.
$ time rpm -qf /var/www/html
$ time rpm -qf /var/www/html
httpd-2.4.10-1.fc20.x86_64
real    0m0.025s
user    0m0.018s
sys     0m0.006s

Using the yum command which gave us four packages and took around 1-plus BLOODY minutes.
$ time yum whatprovides '/var/www/html'
real    1m23.865s
user    0m19.660s
sys     0m0.901s

Now that is something we can improve by using cached result through -C option. Let's try again. But then again, the results are still not entirely accurate.
$ time yum -C whatprovides '/var/www/html'
......
real    0m0.350s
user    0m0.257s
sys     0m0.050s

$ ls -ld /var/www/html/
drwxr-sr-x 1 root apache 40 Oct  4 15:05 /var/www/html/

Unfortunately, yum does not include support for reverting ownership and permissions of any installed files or folders.

Reset the ownership,
$ sudo rpm --setugids httpd
$ ls -ld /var/www/html
drwxr-sr-x 1 root root 40 Oct  4 15:05 /var/www/html/

However, resetting the permissions does not seems to remove back the setguid flag. Weird. Unfortunately, I can't google for any good explanation of such problem.
$ sudo rpm --setugids httpd
$ ls -ld /var/www/html
drwxr-sr-x 1 root root 40 Oct  4 15:05 /var/www/html/