Don't emit histogram checking for LocalFileHeaders if ZIP contains ZIP

Because a ZIP within a ZIP is likely stored a raw bytes, we will see
many LFHs that are not extracted. So don't emit the histogram if we have
a ZIP within a ZIP.

Bug: 873766
Change-Id: I4c42c4a898634b5ab77a4d2dadef685d85810d80
Reviewed-on: https://chromium-review.googlesource.com/c/1416817
Commit-Queue: Daniel Rubery <drubery@chromium.org>
Reviewed-by: Nathan Parker <nparker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623777}
1 file changed