[Extension+Blink] Add bulk removal for an origin to SecurityPolicy

Add SecurityPolicy::RemoveAllOriginAccessWhitelistEntriesForOrigin()
to remove all entries associated with a given origin. This simplifies
the extensions code and is faaaar more efficient, since we don't have
to construct <n> different origin entries and iterate over the list of
possible matches. Instead, we just remove the entry from the map in its
entirety.

No behavior change is expected.

[email protected]

Bug: None
Change-Id: Ibb05221898d4a2539e1a687941526e7ecf09c72a
Reviewed-on: https://chromium-review.googlesource.com/1105287
Commit-Queue: Devlin <[email protected]>
Reviewed-by: Stephen Lanham <[email protected]>
Reviewed-by: Jeremy Roman <[email protected]>
Reviewed-by: Daniel Cheng <[email protected]>
Cr-Commit-Position: refs/heads/master@{#570531}
12 files changed