reenable TabDragging DragToOverviewWindow/1

Fixed by crrev.com/604972 and crrev.com/604715

BUG=900363, 890071
TEST=trybot

Change-Id: I726db69c603595a2f4ec4f49a6976b9f57c737c8
Reviewed-on: https://chromium-review.googlesource.com/c/1314598Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Jun Mukai <mukai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605086}

testing/buildbot/filters/chromeos.single_process_mash.interactive_ui_tests.filter

@@ -40,7 +40,6 @@
 # TabDragging: crbug.com/890071
 -TabDragging/DetachToBrowserInSeparateDisplayTabDragControllerTest.DragBrowserWindowWhenMajorityOfBoundsInSecondDisplay/0
 -TabDragging/DetachToBrowserTabDragControllerTest.DetachToOwnWindowWhileInImmersiveFullscreenMode/1
--TabDragging/DetachToBrowserTabDragControllerTest.DragToOverviewWindow/1
 -TabDragging/DetachToBrowserTabDragControllerTest.DragToSeparateWindow/1
 -TabDragging/DetachToBrowserTabDragControllerTest.DragWithMaskedWindows/0
 -TabDragging/DetachToBrowserTabDragControllerTest.DragWithMaskedWindows/1