Fix a crash where we are checking IsConnected(). If you look into the ...

Fix a crash where we are checking IsConnected().  If you look into the 
implementation of IsConnected() on windows, you'll find that it can
synchronously check if the socket is connected.  This makes it so that
a CHECK (or DCHECK) on this attribute is dependent on the peer.  The peer
could send us a TCP-FIN at any time - even 1 nanosecond before our call
to IsConnected().  We can only use CHECK(!IsConnected()) to check before
we connect, we simply can't use it at runtime.

I searched the code and found 4 other instances of this broken check.  Most
were DCHECKs, which is good, but I've removed them just the same.

Turns out our MockSockets have a mechanism for simulating this error, but it
wasn't tested nor plumbed through the MockSSLClientSocket.  In the process
I added a couple of basic proxy test cases, which may be slightly redundant
with other test cases that are more advanced.  But they seem like a good
idea to cover anyway.  Added 6 tests in total.


BUG=53099
TEST=ProxyTunnelGetHangup, RecycleDeadSSLSocket


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=57295

[eroman, 2010-08-25 05:26:47]

LGTM

http://codereview.chromium.org/3107036/diff/8001/9003
File net/http/http_stream_parser.cc (right):

http://codereview.chromium.org/3107036/diff/8001/9003#newcode582
net/http/http_stream_parser.cc:582: if (!connection_->socket() ||
!connection_->socket()->IsConnected())
we weren't previously checking to see if socket is non-NULL, under what
circumstances is that valid?

[Mike Belshe, 2010-08-25 06:22:32]

http://codereview.chromium.org/3107036/diff/8001/9003
File net/http/http_stream_parser.cc (right):

http://codereview.chromium.org/3107036/diff/8001/9003#newcode582
net/http/http_stream_parser.cc:582: if (!connection_->socket() ||
!connection_->socket()->IsConnected())
On 2010/08/25 05:26:47, eroman wrote:
> we weren't previously checking to see if socket is non-NULL, under what
> circumstances is that valid?

It's not really valid.  I was just making it the same as the check on line 593.