Are all of these converted to CR LF (\r\n)?
Nope. The HTML4 spec here is unclear on what a line break is, but what browsers do, and what HTML5 has gone on to standardise is that only CR and LF are involved:
replace every occurrence of a "CR" (U+000D) character not followed by a "LF" (U+000A) character, and every occurrence of a "LF" (U+000A) character not preceded by a "CR" (U+000D) character, by a two-character string consisting of a U+000D CARRIAGE RETURN "CRLF" (U+000A) character pair
(IE doesn't quite conform to this exactly, as it treats LFCR as a single newline. But it's close enough.)