[PATCH] Don't merge constructors with initializer lists to one line in WebKit style.

[Alexander Kornienko]

  The alternative approach seems to handle correctly this specific case (plus the case of a short standalone compound statement, that we probably also don't want to merge). It looks looks convoluted, than what would be here after gating the change on DryRun and handling all other corner cases.

http://llvm-reviews.chandlerc.com/D2455