hg: jdk9/client/jdk: 8022640: ServiceRegistry (used by ImageIO) lack synchronization

[prasanta.sadhukhan at oracle.com]

Changeset: c047d37dd495
Author:    jdv
Date:      2016-02-01 15:39 +0530
URL:       http://hg.openjdk.java.net/jdk9/client/jdk/rev/c047d37dd495

8022640: ServiceRegistry (used by ImageIO) lack synchronization
Reviewed-by: prr, psadhukhan

! src/java.desktop/share/classes/javax/imageio/spi/ServiceRegistry.java
+ test/javax/imageio/spi/ServiceRegistrySyncTest.java