问题
As the question states basically. If you have X-UA-Compatible in both your HTTP headers and a meta tag on your document, and they conflict, which one gets respected by IE?
回答1:
TL;DR: The meta tag wins
I found the following (updated) flowchart here (link is broken) and associated blog post that provides an explanation of how IE9 determines document mode:
来源：https://stackoverflow.com/questions/9128739/which-x-ua-compatible-takes-precedence-http-header-or-meta-tags