The INVALIDATE_USER_TOKEN_PERSISTENCE and
INVALIDATE_USER_PROJECT_TOKEN_PERSISTENCE callbacks were meant to
clean up invalid tokens from the token storage layer. Now that the
sql token driver has been removed, we don't need them any more. This
commit removes those notifications and refactors the places where
notifications are still needed, making them more specific and not
eluding to token persistence.
This commit also removes a significant amount of logic from the
assignment API that used to notify the token API when assignments
were deleted. This made sense when tokens were written to disk
because there was an opportunity to invalidate them when users were
removed from projects. This is no longer needed since we do
validation online and we don't persist tokens anymore.
Change-Id: I100b7416e8ba61eb4ea2c2eb4962e952a53ea388
c7658abfd6