tst_QGraphicsView::itemsInRect_cosmeticAdjust is flaky on Ubuntu in CI

********* Start testing of tst_QGraphicsView *********
Config: Using QtTest library 5.11.0, Qt 5.11.0 (x86_64-little_endian-lp64 shared (dynamic) debug build; by GCC 5.4.0 20160609)
PASS   : tst_QGraphicsView::initTestCase()
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(nil)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 0, 300, 100)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 0, 100, 300)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(200, 0, 100, 300)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 200, 300, 100)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 0, 300, 99)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 0, 99, 300)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(201, 0, 99, 300)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 201, 300, 99)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(nil)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 0, 300, 100)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 0, 100, 300)
FAIL!  : tst_QGraphicsView::itemsInRect_cosmeticAdjust(200, 0, 100, 300) 'QTest::qWaitForWindowActive(&view)' returned FALSE. ()
   Loc: [tst_qgraphicsview.cpp(1658)]
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 200, 300, 100)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 0, 300, 99)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 0, 99, 300)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(201, 0, 99, 300)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 201, 300, 99)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 0, 300, 98)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 0, 98, 300)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(202, 0, 98, 300)
PASS   : tst_QGraphicsView::itemsInRect_cosmeticAdjust(0, 202, 300, 98)
PASS   : tst_QGraphicsView::cleanupTestCase()
Totals: 23 passed, 1 failed, 0 skipped, 0 blacklisted, 26266ms
********* Finished testing of tst_QGraphicsView *********