Roll optimization-guide from aa7d8cdc0d0b to 7521f446d4f6

https://chrome-internal.googlesource.com/chrome/components/optimization_guide.git/+log/aa7d8cdc0d0b..7521f446d4f6

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://skia-autoroll.corp.goog/r/optimization-guide-chromium
Please CC chrome-intelligence-core@google.com,sophiechang@chromium.org on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

Bug: None
Change-Id: I3fa8a10aeadb5e93965db93a7d5ad24736a6ca71
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5617214
Bot-Commit: chromium-internal-autoroll <chromium-internal-autoroll@skia-corp.google.com.iam.gserviceaccount.com>
Commit-Queue: chromium-internal-autoroll <chromium-internal-autoroll@skia-corp.google.com.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1313040}