Clean up HttpResponseHeaders::IsKeepAlive. Use the...

Clean up HttpResponseHeaders::IsKeepAlive.  Use the parsed
HTTP version in the http_version_ member.  Pass NULL to
EnumerateHeader.

R=eroman

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=11045

[wtc, 2009-03-04 23:50:36]

1. Re: the 'iter' change: EnumerateHeader does not change
*iter when it returns false, so the original code is
correct.  However, this is not documented.  So it'd be
better to explicitly set iter to NULL again before the
second EnumerateHeader call.  But since we're only
interested in the first "connection" or "proxy-connection"
header, we can simply pass NULL to EnumerateHeader.

2. I added several new test cases for IsKeepAlive.  The
second test case is failing now.  So please let me know if
I should fix our code or just remove the first two test
cases, which cannot happen the way HttpNetworkTransaction
uses IsKeepAlive.

Thanks for your advice!

[eroman, 2009-03-05 07:26:51]

LGTM, good cleanup.

I wouldn't worry about the first two test cases.

Since in HTTP/0.9 there is no concept of statusline or headers, it probably
doesn't make sense to be reached with those inputs (parsing the response body as
if it where headers; http_network_transaction decides if it is 0.9 before
feeding data into the header parser).