Bug 1499380 [wpt PR 13543] - Add tests for screenLeft and `screenTo…

…p`, a=testonly

Automatic update from web-platform-testsAdd tests for `screenLeft` and `screenTop`

Matches w3c/csswg-drafts#2669.

Note that `screenX` and `screenY` themselves aren't tested at all:
web-platform-tests/wpt#5471

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Update screenLeftTop.html
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Merge pull request #13543 from web-platform-tests/foolip/screenLeftTop

Add tests for `screenLeft` and `screenTop`
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wpt-commits: 384330eb99484763b94f4a986fa8cacabb579739, 9b13cb18deeccf3e1da44e227c343531deffa1fb, 9419b7f7d685502b8c900dbce2500dfdedb0edec
wpt-pr: 13543

UltraBlame original commit: ced4e022b06516738488d8b9f1c469661220f5df

testing/web-platform/tests/css/cssom-view/screenLeftTop.html

@@ -0,0 +1,196 @@
+<
+!
+DOCTYPE
+html
+>
+<
+link
+rel
+=
+"
+help
+"
+href
+=
+"
+https
+:
+/
+/
+drafts
+.
+csswg
+.
+org
+/
+cssom
+-
+view
+/
+#
+dom
+-
+window
+-
+screenleft
+"
+>
+<
+link
+rel
+=
+"
+help
+"
+href
+=
+"
+https
+:
+/
+/
+drafts
+.
+csswg
+.
+org
+/
+cssom
+-
+view
+/
+#
+dom
+-
+window
+-
+screentop
+"
+>
+<
+script
+src
+=
+"
+/
+resources
+/
+testharness
+.
+js
+"
+>
+<
+/
+script
+>
+<
+script
+src
+=
+"
+/
+resources
+/
+testharnessreport
+.
+js
+"
+>
+<
+/
+script
+>
+<
+script
+>
+test
+(
+(
+)
+=
+>
+{
+assert_equals
+(
+typeof
+window
+.
+screenLeft
+"
+number
+"
+"
+screenLeft
+type
+"
+)
+;
+assert_equals
+(
+window
+.
+screenLeft
+window
+.
+screenX
+"
+alias
+of
+screenX
+"
+)
+;
+}
+"
+screenLeft
+"
+)
+;
+test
+(
+(
+)
+=
+>
+{
+assert_equals
+(
+typeof
+window
+.
+screenTop
+"
+number
+"
+"
+screenTop
+type
+"
+)
+;
+assert_equals
+(
+window
+.
+screenTop
+window
+.
+screenY
+"
+alias
+of
+screenY
+"
+)
+;
+}
+"
+screenTop
+"
+)
+;
+<
+/
+script
+>