Handle changes to TaskArray class in TaskGraph.
Handle changes to TaskArray class in TaskGraph.

Monotone-Parent: e0682ecebd3f4d7008e265a5f2c4652134248d88
Monotone-Revision: ec7f62144da1749558ca4cf421ea81d917a87c90

FrancisRussell/desola,FrancisRussell/desola,FrancisRussell/desola