Fix use-after-free in HttpFetcher's code.
Calling HttpFetcherDelegate::TransferComplete() or TransferTerminated()
on the transfer delegate is allowed to destroy the HttpFetcher that
called it.
While we don't do this from our code, the unittests excercise this path
destroying the HttpFetcher. This code prevents a use-after-free once
the TransferComplete() delegate method is called from CurlPerformOnce().
Bug: chromium:595068
TEST=USE="clang asan" FEATURES=test emerge-link update_engine
Change-Id: I73317eae092ed4ac1ccad5c3fc68b25ad8bb387c
1 file changed