gir1.2-javascriptcoregtk-3.0 2.4.6-1ubuntu1 (amd64 binary) in ubuntu vivid

 JavaScriptCore is the JavaScript engine used in WebKit. It consists
 of the following building blocks: lexer, parser, start-up interpreter
 (LLInt), baseline JIT, a low-latency optimizing JIT (DFG), and a
 high-throughput optimizing JIT (FTL).
 .
 This build comes from the GTK+ port of WebKit (API version 3.0).
 .
 This package contains the introspection data, which can be used by
 packages using the GIRepository format to generate dynamic bindings.