This is for https://bugzilla.mozilla.org/show_bug.cgi?id=1383977.
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The patch provides FFI access to Gecko's SeenPtrs type from Rust, in
order to record what has already been measured when measuring Arcs. (The
SeenPtrs must be initialized on the Gecko side because the same table is
reused for measuring all Elements within a window, because Elements can
share ComputedValues.) I have confirmed with DMD that this is working
correctly.
The patch also introduces MallocSizeOfRepeats, which is like
MallocSizeOf but takes a SizeOfState, which holds a SeenPtrs table.
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- [X] These changes fix #__ (github issue number if applicable).
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Source-Repo: https://github.com/servo/servo
Source-Revision: 32e2e546ac452cf83a0fb7e1d4521df23ec5eeda
4eedf2ff38