Not even close to the same feature. Firefox has a “smart keywords” feature, which you need to set up manually by making special bookmarks and setting keywords yourself. (Usually right click a search field and choose “Add a keyword for this search”). The feature has nothing to do with the OpenSearch plugins used for Firefox’s search box. (Though there are some Firefox extensions that make the address bar use those).
You’re right that Chrome’s omnibar lets you search by typing a keywords and a search query, but it’s very different. For one thing, it’s constantly adding search engines. When you use a search field, Chrome remembers it. You don’t have to add that search engine yourself. This is useful. For example, I can search StackOverflow by typing stackoverflow.com + Tab, and that feature just kind of appears when I want it. I didn’t need to do anything to get it there. The browser just happened to go “hey, maybe you’d like to do a search?” when I was typing the URL.
Also, it autocompletes search keywords. I don’t actually have to type stackoverflow.com. I just type stack and it figures out the rest.
On a related note, it’s also a lot easier to edit Chrome’s list of search engines: chrome://settings/searchEngines
So, to your ill-informed claim: no.
