Surface ERR_SPDY_SESSION_ALREADY_EXISTS to the proxy delegate.

Surface ERR_SPDY_SESSION_ALREADY_EXISTS to the proxy delegate.

Add a regression test, confirming that sessions which race host
resolutions don't fail network transactions.

BUG=334413
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=278346

[Johnny, 2014-06-19 04:08:43]

https://codereview.chromium.org/346713003/diff/1/net/http/http_proxy_client_s...
File net/http/http_proxy_client_socket_pool.cc (right):

https://codereview.chromium.org/346713003/diff/1/net/http/http_proxy_client_s...
net/http/http_proxy_client_socket_pool.cc:250: return
ERR_PROXY_CONNECTION_FAILED;
Is there a particular rationale for converting to this error, rather than
surfacing the underlying error?

[Ryan Hamilton, 2014-06-19 04:25:39]

lgtm

https://codereview.chromium.org/346713003/diff/1/net/http/http_proxy_client_s...
File net/http/http_proxy_client_socket_pool.cc (right):

https://codereview.chromium.org/346713003/diff/1/net/http/http_proxy_client_s...
net/http/http_proxy_client_socket_pool.cc:250: return
ERR_PROXY_CONNECTION_FAILED;
On 2014/06/19 04:08:43, Johnny wrote:
> Is there a particular rationale for converting to this error, rather than
> surfacing the underlying error?

Wow, This code is a blast from the past. I *think* I basically lifted this code
from http_proxy_client_socket and it seems to do the same thing :| I *suspect*
there might have been some desire to avoid confusing proxy errors with transport
errors, but frankly, I'm not sure.

[Johnny, 2014-06-19 05:07:18]

The CQ bit was checked by jgraettinger@chromium.org

[commit-bot: I haz the power, 2014-06-19 05:10:23]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jgraettinger@chromium.org/346713003/1

[commit-bot: I haz the power, 2014-06-19 12:51:53]

Change committed as 278346