TestWebServer needs to use a free port.

TestWebServer needs to use a free port.

Instead of a hardcoded port that could be taken.

BUG=

Committed: https://crrev.com/c4a3f88c4434e86057a8c7ae4e109b8be4138d8f
Cr-Commit-Position: refs/heads/master@{#292014}

[hush (inactive), 2014-08-22 18:18:17]

If you don't 4444 or 4445 port is taken on the device, you will get this error:

C   38.945s Main  java.net.BindException: bind failed: EADDRINUSE (Address
already in use)
C   38.945s Main  	at libcore.io.IoBridge.bind(IoBridge.java:99)
C   38.945s Main  	at java.net.PlainSocketImpl.bind(PlainSocketImpl.java:132)
C   38.945s Main  	at java.net.ServerSocket.<init>(ServerSocket.java:105)
C   38.945s Main  	at java.net.ServerSocket.<init>(ServerSocket.java:74)
C   38.945s Main  	at
javax.net.ssl.SSLServerSocket.<init>(SSLServerSocket.java:53)
C   38.945s Main  	at
com.android.org.conscrypt.OpenSSLServerSocketImpl.<init>(OpenSSLServerSocketImpl.java:36)
C   38.945s Main  	at
com.android.org.conscrypt.OpenSSLServerSocketFactoryImpl.createServerSocket(OpenSSLServerSocketFactoryImpl.java:62)
C   38.946s Main  	at
org.chromium.net.test.util.TestWebServer$ServerThread.<init>(TestWebServer.java:551)
C   38.946s Main  	at
org.chromium.net.test.util.TestWebServer.<init>(TestWebServer.java:122)

[hush (inactive), 2014-08-23 00:55:33]

PTAL

[Yaron, 2014-08-25 19:23:22]

On 2014/08/23 00:55:33, hush wrote:
> PTAL

Is there a bug for this? Are we seeing this on the bots somewhere? I think we
haven't seen it in practice because you don't have multiple test servers running

[hush (inactive), 2014-08-25 20:14:13]

On 2014/08/25 19:23:22, Yaron wrote:
> On 2014/08/23 00:55:33, hush wrote:
> > PTAL
> 
> Is there a bug for this? Are we seeing this on the bots somewhere? I think we
> haven't seen it in practice because you don't have multiple test servers
running

We don't see that on bots. However, it happened when I ran tests locally
probably because 
other applications were using the ports 4444, 4445.
I am trying to use TestWebServer for Android CTS tests (by copying this code to
android cts). 
And I see the socket error when I run them without this fix.

[Yaron, 2014-08-26 17:52:24]

lgtm

[hush (inactive), 2014-08-26 20:56:39]

The CQ bit was checked by hush@chromium.org

[commit-bot: I haz the power, 2014-08-26 20:58:25]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/hush@chromium.org/502503003/40001

[commit-bot: I haz the power, 2014-08-26 22:53:26]

Committed patchset #3 (40001) as e5a72f7e4b9609aa111c90908cad7e44d5be73c0

[commit-bot: I haz the power, 2014-09-10 02:46:48]

Patchset 3 (id:??) landed as
https://crrev.com/c4a3f88c4434e86057a8c7ae4e109b8be4138d8f
Cr-Commit-Position: refs/heads/master@{#292014}