clang-format: Fix corner case working around one-per-line dict literals.

Before:
  var object_literal_with_long_name = {
    a: 'aaaaaaaaaaaaaaaaaa', b: 'bbbbbbbbbbbbbbbbbb'
  };

After:
  var object_literal_with_long_name = {
    a: 'aaaaaaaaaaaaaaaaaa',
    b: 'bbbbbbbbbbbbbbbbbb'
  };

llvm-svn: 209296