Chromebook is a bit different as a development platform. As already mentioned, most any programmer's editor will have an extension to help nest and pretty print XML. If you can enable Linux on the Chromebook, a full featured integrated development environment (IDE) like those from Jetbrains will support XML parsing.
JetBrains XML
https://www.jetbrains.com/help/idea/working-with-xml.html

To bring the XML into Google Docs you might look at its IMPORTXML feature.

IMPORTXML
https://support.google.com/docs/answer/3093342?hl=en


For processing the XML files in Windows you might look at a commercial XML tools$ like Altova like XML Spy. These specialty editors can also help devise XSLT transforms for the XML documents, say to generate XHTML for easier browser display on different size devices, or XSD definitions for importing data into Excel or a database.

XML Spy
https://www.altova.com/xmlspy-xml-editor
 
In my experience XML documents from the Integrated Library Services (ILS) can hold borrower/patron online registration data so an XSLT transform or XSD will format or describe the XML so that the ILS recognizes borrower data- sometimes csv or pipe delimited data. 
ILS notices and reports can use XML as an intermediate output format and again use an XSLT transform to generate html or plain text email messages. I have also seen an older library "people count" sensor providing vendor specific XML documents containing near real time counts and status from an individual doorway sensor. 

If the XML represents SOAP/WSDL protocol code, tools like SoaUI and ReadyAPI can help portray the code and generate protocol transactions. 

SoapUI
https://www.soapui.org/downloads/soapui/
ReadyAPI

Let us know what you use, especially on a Chromebook.

Wil Blake
www.fcpl.org