RFR: JDK-8157453 - Convert DependencyContext_test to GTest

[Jesper Wilhelmsson]

Hi,

Please review this test conversion of the DependencyContext tests to GTest.

Bug: https://bugs.openjdk.java.net/browse/JDK-8157453
Webrev: http://cr.openjdk.java.net/~jwilhelm/8157453/webrev.00/

Thanks,
/Jesper