Quick little WordPress plugin to embed PDFs with Google's PDF viewer. See: https://community.nten.org/communities/community-home/digestviewer/viewthread?MessageKey=98bbef1e-d60f-453b-a039-562cfbe52b26&CommunityKey=76218446-efc9-4c49-9462-59b5d88daecb&tab=digestviewer&UserKey=3f274014-ea5f-4f43-a232-e59886306781&sKey=9dd0bd09908d46de93f9#bm0

nten-pdf-embed-shortcode.php

<?php
/*
Plugin Name: Google PDF Viewer Shortcode
Description: Display a PDF in the browser with Google's PDF viewer. Usage: [pdf]http://example.org/some-public-document.pdf[/pdf]. Can specify optional width and height attribrutes like this [pdf width="100" height="100"]http://example.org/a-very-tiny-document.pdf[/pdf]
Version: 1.0
Author: Mark Root-Wiley
Author URI: https://mrwweb.com
*/
/* a shortcode for embedding PDFs via Google Docs viewer */
function nten_pdf_shortcode( $atts, $content = '' ) {

  if( '' === $content || '.pdf' !== substr( $content, -4 ) ) {
    return;
  }

  $atts = shortcode_atts( array(
    'width' => '600',
    'height' => '775'
  ), $atts, 'pdf' );

  return '<iframe src="https://docs.google.com/viewer?url=' . esc_url( $content ) . '&embedded=true" style="width:' . intval( $atts['width'] ) . 'px; height:' . intval( $atts['height'] ) . 'px;" frameborder="0" class="us-embedded-pdf"></iframe>';
}
add_shortcode( 'pdf', 'nten_pdf_shortcode' );