hg: jdk/sandbox: 8219548: Better Null paramenter checking in ToolProvider

[chris.hegarty at oracle.com]

Changeset: 03924ad3f4d0
Author:    lancea
Date:      2019-02-26 13:14 -0500
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/03924ad3f4d0

8219548: Better Null paramenter checking in ToolProvider
Reviewed-by: lancea, alanb, jjg
Contributed-by: Philipp Kunz <philipp.kunz at paratix.ch>

! src/java.base/share/classes/java/util/spi/ToolProvider.java
! test/jdk/java/util/spi/ToolProviderTest.java