clang-format: [JS] Try not to break in container literals.

Before:
  var obj = {
    fooooooooo:
        function(x) { return x.zIsTooLongForOneLineWithTheDeclarationLine(); }
  };

After:
  var obj = {
    fooooooooo: function(x) {
      return x.zIsTooLongForOneLineWithTheDeclarationLine();
    }
  };

llvm-svn: 222892