message: refactor(language-service): Remove unused class and method
  PR Close
diff: @@ -704,15 +704,6 @@ function spanAt(sourceFile: ts.SourceFile, line: number, column: number): Span|u
  }
  }
  -function chainedMessage(chain: DiagnosticMessageChain, indent = ''): string {
  - return indent + chain.message + (chain.next ? chainedMessage(chain.next, indent + ' ') : '');
  -}
  -
  -class DiagnosticMessageChainImpl implements DiagnosticMessageChain {
  - constructor(public message: string, public next?: DiagnosticMessageChain) {}
  - toString(): string { return chainedMessage(this); }
  -}
  -
  function convertChain(chain: FormattedMessageChain): DiagnosticMessageChain {
  return {message: chain.message, next: chain.next ? convertChain(chain.next) : undefined};
  }
  