RFR [13] 8217976: test/jdk/java/net/httpclient/websocket/WebSocketProxyTest.java fails intermittently

[Chris Hegarty]

> On 29 Jan 2019, at 12:31, Daniel Fuchs <daniel.fuchs at oracle.com> wrote:
> 
> ...
> The best would be to use CopyOnWriteArrayList instead
> of synchronizedList(). Otherwise you'd still need to copy the list
> within a synchronize(connections) { } block to prevent CME.

Agreed. Should be good enough for test cleanup.

http://cr.openjdk.java.net/~chegar/8217976/webrev.01/

-Chris.