disk_cache/blockfile: Fix DiskCacheBackendTest.BlockFileMaxSizeLimit

- Avoid overflow in MaxStorageSizeForTable with huge
  caches (not actually used in practice).
- Make the test of oversize cache fail for right reason
  (rather than because of above screw up) by actually
  checking SetMaxSize return.
- That in turn resulted in removing sync failure possibility from
  CacheCreator::[TryCreateCleanupTrackerAndRun]Run ---
  since it didn't work right if Run failed synchronously from async
  TryCreateCleanupTrackerAndRun re-run... which didn't matter before
  since only sync failure used to be trying to use blockfile on
  Android


Change-Id: Ia12df31a558b722edb2271d1c7a673a6856bfd7a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5941998
Commit-Queue: Maks Orlovich <morlovich@chromium.org>
Reviewed-by: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1372144}