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+<!DOCTYPE html><html class="reftest-paged">
+<style>html{font-size:12pt}</style>
+<!-- http example.org uri makes this an oop if with fission -->
+<iframe style="height: 1000vh" src="http://example.org/1743533-1-helper.html"></iframe>
+</html>
+
+<!--
+Some notes about this test.
+To reproduce the problem we just need an oop iframe that spans multiple pages,
+and some content in it that also spans multiple pages. I used text instead
+of a background color because background colors don't show up by default in
+print preview. We're using page mode here and not print preview, so that is
+not technically required here.
+
+We'd like to compare an oop iframe and an in process iframe with the same
+content to make sure they are the same. But some idiosyncracies with scrollbars
+in paged mode cause the rendering not to be exactly the same. Since paged mode
+is just for testing, and printing doesn't have scrollbars, it doesn't seem
+worth digging too much into it.
+
+We compare an iframe with content in it, to a blank iframe, and then we use a
+high minimum accepted number of pixels differing in the fuzz. This then makes
+sure the two documents differ by enough pixels.
+
+Note why we couldn't use other test types:
+
+I tried to write this as a wpt print reftest, it did not reproduce the bug.
+I'm not sure what wpt reftests use to simulate printing, but I suspect it
+is not similar enough to our print preview to trigger the bug.
+
+I tried to add this as a test to layout/base/tests/chrome/test_printpreview.xhtml
+but that is not feasible because that test runs as part of the mochitest-chrome
+suite, which I'm told doesn't even run in e10s mode, and definitely does not get
+run with fission, which is required to reproduce the bug.
+-->