Use ActionView::OutputBuffer#safe_append= from templates
avoid extra method calls for appending newlines

before:

        ');@output_buffer.append= ( content_icon row[:content] );@output_buffer.safe_concat('
');@output_buffer.safe_concat('        ');@output_buffer.append= ( spinner_img );@output_buffer.safe_concat('
');@output_buffer.safe_concat('      </td>
      <td class="content">
        ');@output_buffer.append= ( content_link row[:content] );@output_buffer.safe_concat('
');@output_buffer.safe_concat('      </td>
      <td class="message">
');

after:

        ';@output_buffer.append=( content_icon row[:content] );@output_buffer.safe_append='
        ';@output_buffer.append=( spinner_img );@output_buffer.safe_append='
      </td>
      <td class="content">
        ';@output_buffer.append=( content_link row[:content] );@output_buffer.safe_append='
      </td>
      <td class="message">
';
Merge pull request #9555 from tmm1/optimize-erb

Optimize generated ERB to reduce method calls