Explain two common XSSAuditor corner cases.

Change-Id: Idc316c17dec63531abb3b39f4188d368d0aad0b2
Reviewed-on: https://chromium-review.googlesource.com/706253
Reviewed-by: Chris Palmer <palmer@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#507421}
1 file changed