media: Hook up CdmStorage deletion code

This CL goes throughout the Chromium codebase and puts the deletion code
where necessary so that when kCdmStorageDatabase flag is enabled, the
BrowsingDataRemoverBrowser tests pass. This CL also tests that when
incognito, the CdmStorage.db is not written to disk.

Testing: I enabled kCdmStorageDatabase and ran browser_tests. Without
these changes, the
IncognitoBrowsingDataBrowserTest.StorageDoesntWriteToDisk and
BrowsingDataRemoverBrowserTest.StorageRemovedFromDisk would fail. These
changes now allow these tests to pass when the flag is enabled.

Bug: 1454512
Change-Id: Iadcc69781f7abd3a545f678519c28d6a51000d3a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4936193
Reviewed-by: John Rummell <jrummell@chromium.org>
Commit-Queue: Vikram Pasupathy <vpasupathy@chromium.org>
Reviewed-by: Bo Liu <boliu@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1210620}