Change ownership of the parameters to ServiceWorkerCache:: Put and Match.
These functions used to take unowned raw pointers as arguments. Now the functions own them and they're scoped_ptrs. This both makes ownership clearer and allows for the functions to terminate early without calling their callbacks (needed for a downstream change to run CreateBackend lazily).
Related CLs:
* 1. https://crrev.com/
542703002: Change ownership of the parameters to ServiceWorkerCache:: Put and Match.
2. https://crrev.com/
545533002: Move ServiceWorkerCache backend creation to a lazy init function.
3. https://crrev.com/
548533002: Make ServiceWorkerCacheStorage::CacheLoader::LoadCache synchronous
4. https://crrev.com/
549493002: Expose ServiceWorkerCache objects to ServiceWorkerCacheStorageManager clients.
BUG=392621
Review URL: https://codereview.chromium.org/
542703002
Cr-Commit-Position: refs/heads/master@{#294366}