Bug 1446953 [wpt PR 10092] - Update wpt metadata, a=testonly

wpt-pr: 10092
wpt-type: metadata

testing/web-platform/meta/webdriver/tests/get_window_rect.py.ini

@@ -1,4 +1,6 @@
 [get_window_rect.py]
+  disabled:
+    if not debug and stylo and e10s and (os == "linux") and (version == "Ubuntu 16.04") and (processor == "x86_64") and (bits == 64): wpt-sync Bug 1446953
   [test_handle_prompt_accept]
     expected: FAIL