Jumplists currently write out the entire jumplist every time it is written out. However, it is likely that only a few items change when they are written. We should find a way to reuse the existing icons when writing out the jumplist.

https://bugs.chromium.org/p/chromium/issues/detail?id=40407#c26 also suggests that temp files are written out that end up not being used. These should not be written out either.