Fix bad placeholder string in Preload + SRI tests

R=yhirano@chromium.org

Bug: 677022
Change-Id: Iac6114a810417c115e92aaa7cfb0c2b978d563f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1679139
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Dominic Farolino <dom@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672834}
1 file changed