tst_QDeadlineTimer::stdchrono() is flaky on macOS

********* Start testing of tst_QDeadlineTimer *********
 Config: Using QtTest library 5.11.0, Qt 5.11.0 (x86_64-little_endian-lp64 shared (dynamic) release build; by Clang 8.0.0 (clang-800.0.42.1) (Apple))
 PASS   : tst_QDeadlineTimer::initTestCase()
 PASS   : tst_QDeadlineTimer::basics(precise)
 PASS   : tst_QDeadlineTimer::basics(coarse)
 PASS   : tst_QDeadlineTimer::foreverness(precise)
 PASS   : tst_QDeadlineTimer::foreverness(coarse)
 PASS   : tst_QDeadlineTimer::current(precise)
 PASS   : tst_QDeadlineTimer::current(coarse)
 PASS   : tst_QDeadlineTimer::deadlines(precise)
 PASS   : tst_QDeadlineTimer::deadlines(coarse)
 PASS   : tst_QDeadlineTimer::setDeadline(precise)
 PASS   : tst_QDeadlineTimer::setDeadline(coarse)
 PASS   : tst_QDeadlineTimer::expire(precise)
 PASS   : tst_QDeadlineTimer::expire(coarse)
 PASS   : tst_QDeadlineTimer::stdchrono(precise)
 FAIL!  : tst_QDeadlineTimer::stdchrono(coarse) 'diff.count() < 3*minResolution/2' returned FALSE. (1152)
    Loc: [tst_qdeadlinetimer.cpp(518)]
 PASS   : tst_QDeadlineTimer::cleanupTestCase()
 Totals: 15 passed, 1 failed, 0 skipped, 0 blacklisted, 3973ms
 ********* Finished testing of tst_QDeadlineTimer *********

/Users/qt/work/qt/qtbase/tests/auto/corelib/kernel/qdeadlinetimer/target_wrapper.sh  ./tst_qdeadlinetimer stdchrono
 ********* Start testing of tst_QDeadlineTimer *********
 Config: Using QtTest library 5.11.0, Qt 5.11.0 (x86_64-little_endian-lp64 shared (dynamic) release build; by Clang 8.0.0 (clang-800.0.42.1) (Apple))
 PASS   : tst_QDeadlineTimer::initTestCase()
 FAIL!  : tst_QDeadlineTimer::stdchrono(precise) 'diff.count() < 3*minResolution/2' returned FALSE. (947)
    Loc: [tst_qdeadlinetimer.cpp(510)]
 PASS   : tst_QDeadlineTimer::stdchrono(coarse)
 PASS   : tst_QDeadlineTimer::cleanupTestCase()
 Totals: 3 passed, 1 failed, 0 skipped, 0 blacklisted, 3102ms
 ********* Finished testing of tst_QDeadlineTimer *********