Can I get root access on my Nexus 4 without installing custom bootloader, recovery or ROM? I own a Nexus 4 device and I want to just get root access on my phone so that I can install applications such as AdBlock etc.

I was able to find tutorials online guiding how to root the Nexus phone. But in all those they flash a custom recovery and have to install a custom ROM. 

I don't want to install any custom recovery or ROM. 

Is it possible to just root my phone without doing those?
The Nexus Root Toolkit is the way to go, tho note that to unlock the bootloader, you will have to wipe your device.  However, you'll only have to do this once, so when Google's next update removes your root priveleges, you can just run the Root utility in the toolkit.  If the toolkit can't reboot your Nexus 4 into the bootloader, you can do it manually with adb:

adb reboot-bootloader


in cmd and then run the toolkit's Root. If it just reboots normally, try again and it should eventually boot into a recovery tool.  Choose the reboot into system option and it will prompt to fix the su binary permissions and you'll be rooted again.