Replaces \TestingAccessWrapper (defined in core) with
\Wikimedia\TestingAccessWrapper (defined in the composer package
wikimedia/testing-access-wrapper).
See https://gerrit.wikimedia.org/r/#/q/topic:librarize-testing-access-wrapper
for downstream patches.
The core version of the class is kept around for a while to avoid
circular dependency problems.
Bug: T163434
Change-Id: I52cc257e593da3d6c3b01a909e554a950225aec8
This adds a structure test that verifies all registered ContentHandlers
will return a valid content object (as determined by
Content::isValid()), when makeEmptyContent() is called. Additionally, if
the handler extends TextContentHandler, it will verify it is an instance
of TextContentHandler::getContentClass().
This is a structure test so it is run for content handlers created by
extensions as well.
Change-Id: Idd67d824f2f7cc1819b1d8b186be058e63c4513d
