456940 Work around NPE in getActiveWorkbenchWindow in tests on Hudson

- Remove unused parameter in ElementUtils, which would require calling
  the problematic getActiveWorkbenchWindow in the test.
- Do an extra call to getActiveWorkbenchWindow() and ignore potential
  exceptions before the first time the method is needed in the
  IUPropertyPagesTest.

Bug: 456940
Change-Id: Ie3a38c2576ebc96e831ff2eb685a8c595c3ae5ff
4 files changed