Bug 938131 - Simplify dom::ErrorResult::ReportJSExceptionFromJSImplementation. r=bz.

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extra : rebase_source : db7b8edd1aec3aff7240b1323c00546d2e332112
Bug 938544 - Add support for a Chrome-only constructor in WebIDL. r=bz.

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extra : rebase_source : e36fef0090d57947ceae6c2fc11bea8b115423e4