This reverts commit 5f06efb318, which
reverted 9335363789, which makes
the deprecated property AbstractBlock::mReason private.
After 9335363789, AbstractBlock::mReason is obsolete, since the block
reason is now stored as a CommentStoreComment, AbstractBlock::reason.
Change-Id: Ica0a74be90383689ca8e4cfe6d0fb25c9a5942c5