Change expectation file of pointerevent_coalesced_events_attributes.html to...

Change expectation file of pointerevent_coalesced_events_attributes.html to match the output on Mac 10.13

The wpt test pointerevent_coalesced_events_attributes.html is flaky on
Mac10.13 Tests bot, because its running result is different from the
default expectation file. I add a new expectation file for Mac10.13.

TBR=lanwei@chromium.org,nzolghadr@chromium.org

Bug: 1015254
Change-Id: I0795c7154d33689a80c8fa9a99433d7134678589
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1866993Reviewed-by: Lan Wei <lanwei@chromium.org>
Commit-Queue: Lan Wei <lanwei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707054}

third_party/blink/web_tests/platform/mac-mac10.13/external/wpt/pointerevents/extension/pointerevent_coalesced_events_attributes-expected.txt

+This is a testharness.js-based test.
+PASS touch coalesced events attributes in pointerevents
+PASS touch pointercancel should not have any coalesced events
+PASS touch pointerover should not have any coalesced events
+PASS touch pointerenter should not have any coalesced events
+PASS touch pointerdown should not have any coalesced events
+FAIL touch pointermove should have >2 coalesced events as main thread is busy.
+PASS touch pointermove coalesced events should all be marked as trusted.
+PASS touch time stamps of coalesced events must be ascending.
+PASS touch pointermove coalesced events should all bubbles and cancelable as false.
+PASS touch pointerup should not have any coalesced events
+PASS touch pointerout should not have any coalesced events
+PASS touch pointerleave should not have any coalesced events
+Harness: the test ran to completion.
+