I was trying to open hierarchy viewer of web apps using google nexus 4 . But it has not working. Then i am searching some form and sites regarding this issue but there are telling the way root the device then If root the device may be void the warranty. Is there any way to open hierarchy. i saw one site regarding hierarchy but there are mentioning like void the warranty then we can revoke the warranty. Here my concern is it correct? can we revoke the warranty?
For security purposes, hierarchyviewer only works on debug / developer devices.
The Nexus 4 does qualify, but you WILL need to unlock the phone first before you can do so. Since you're concerned with warranty, then you shouldn't do that.
The closest thing you can do is to apply Romain Guy's ViewServer romainguy/ViewServer on your application, then you can use HierarchyViewer on your app.
(Note: Yes, you can relock the bootloader and unroot from guides in XDA, but it is up to you if you want to do that and pretend your warranty still holds.)