net: plumb DnsRRResolver from IOThread to HttpNetworkSession.

net: plumb DnsRRResolver from IOThread to HttpNetworkSession.

This patch gets us most of the way. The next patch finishes plumbing
into the SSL client socket pool.

BUG=none
TEST=none

[willchan no longer on Chromium, 2010-10-05 04:33:08]

LGTM

http://codereview.chromium.org/3533013/diff/1/3
File chrome/browser/io_thread.h (right):

http://codereview.chromium.org/3533013/diff/1/3#newcode29
chrome/browser/io_thread.h:29: class DnsRRResolver;
Nit: I think we generally sort these alphabetically.

http://codereview.chromium.org/3533013/diff/1/6
File chrome/browser/net/connection_tester.cc (right):

http://codereview.chromium.org/3533013/diff/1/6#newcode75
chrome/browser/net/connection_tester.cc:75: delete dnsrr_resolver_;
You should delete in the reverse order of construction.  net::HttpCache may be
holding the last references to
net::HttpNetworkLayer=>net::HttpNetworkSession=>etc, so its destructor may still
try to access dnsrr_resolver_, which would be invalid in your current code.

http://codereview.chromium.org/3533013/diff/1/7
File chrome/service/net/service_url_request_context.cc (right):

http://codereview.chromium.org/3533013/diff/1/7#newcode60
chrome/service/net/service_url_request_context.cc:60: delete dnsrr_resolver_;
ditto

http://codereview.chromium.org/3533013/diff/1/22
File net/socket/ssl_client_socket_pool.cc (right):

http://codereview.chromium.org/3533013/diff/1/22#newcode343
net/socket/ssl_client_socket_pool.cc:343: client_socket_factory_,
host_resolver_, dnsrr_resolver_,
80 columns