Allow forcing TestWebServer to use a specific port number.

Allow forcing TestWebServer to use a specific port number.

Commit c4a3f88c4434e86057a8c7ae4e109b8be4138d8f ("TestWebServer needs to
use a free port") has caused TestWebServer to use a random port number
in each invocation.

This does not play well with tests that assume the server will be
running on a specific port (for example, an HTML asset trying to do XHR
whose contents cannot be changed at runtime).

start() and startSsl() can now be passed an optional port number; if it
is being used, the server will fail to start like it did before the
commit mentioned above.

R=hush@chromium.org, yfriedman@chromium.org

Committed: https://crrev.com/b4e712c20bf06821c8a05c78886b3fc7dd96b887
Cr-Commit-Position: refs/heads/master@{#300151}

[Raphael Kubo da Costa (rakuco), 2014-10-17 16:02:47]

PTAL

Unfortunately the problem I'm trying to fix does not affect any test in
android_webview/, but is causing problems for us downstream in Crosswalk, as
there are a few tests for CORS that rely on packaged HTML apps doing XHR to a
TestWebServer.

[Yaron, 2014-10-17 19:02:05]

lgtm

[Raphael Kubo da Costa (rakuco), 2014-10-17 19:28:57]

The CQ bit was checked by raphael.kubo.da.costa@intel.com

[hush (inactive), 2014-10-17 19:29:53]

lgtm

thanks!

[commit-bot: I haz the power, 2014-10-17 19:30:24]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/666513002/1

[commit-bot: I haz the power, 2014-10-17 20:04:21]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-17 20:06:08]

Patchset 1 (id:??) landed as
https://crrev.com/b4e712c20bf06821c8a05c78886b3fc7dd96b887
Cr-Commit-Position: refs/heads/master@{#300151}