We should create separate issues for each module/thing that uses drupal_http_request() I think and then finally remove it. Filling as major, but it needs to happen unless we want to ship with both drupal_http_request() and the guzzle library.
Suggested list of issues, based on
grep -Rl drupal_http_request:
and then finally the removal of the function, including the complete removal of HttpRequestTest.php I guess, unless we want to rename and keep that to ensure that we're not introducing any bugs? (Maybe just port it to make sure and report any issues upstream including fixes and test coverage).
PASSED: [[SimpleTest]]: [MySQL] 54,321 pass(es). View
FAILED: [[SimpleTest]]: [MySQL] 54,305 pass(es), 1 fail(s), and 0 exception(s). View