Update ContentTransformer to access ContentHandler::preLoadTransform through the service.
Prepare object to hold a data that required for ContentHandler::preLoadTranform params.
This is a fully backwards compatible change.
We are doing hard deprecation via MWDebug::detectDeprecatedOverride.
However, with the ContentHandler calling Content and
Content calling ContentHandler, it doesn't matter whether
callers use Content or ContentHandler. This will allow us
to naturally convert all callers.
Bug: T287157
Change-Id: I89537e1e7d24c6e15252b2b51890a0bd81ea3e6b
42442e01ff