I have used the same meta that HTML5 Boilerplate is using, and the W3C HTML validator complains:
Bad value X-UA-Compatible for attribute http-equiv on element meta.
<meta http-equiv='X-UA-Compatible' content='IE=edge,chrome=1'>
What is wrong with this meta tag?
Either X-UA-Compatible is not "standard" HTML (FSVO "standard" that involves appearing on a publicly editable wiki page referenced by the specification) or the Validator isn't up to date with the current status of that wiki.
At the time of writing (20130326) X-UA-Compatible appears on the wiki page under a section that states: "The following proposed extensions do not yet conform to all the registration requirements in the HTML spec and are therefore not yet allowed in valid documents." So the validator is correct to reject this value.