I might not have read all the responses but I get that they aren't answering your question.
Rather than opening in the facebook browser vs chrome browser you're saying a link is taking you to facebook.com via chrome rather than simply opening your facebook app.
Those settings are found here...
The comment made me smile. The same can be said for nearly every app.
I personally haven't noticed much of a drain on my battery. It's only in use when you are actively using the phone, otherwise it's sleeping.
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