For approach 2: (Which I recommend) Check out:
https://github.com/mozilla/pdf.js/
PDF.js is Portable Document Format (PDF) viewer that is built with HTML5.
PDF.js is community-driven and supported by Mozilla Labs. Our goal is to create a general-purpose, web standards-based platform for parsing and rendering PDFs.
EDIT: For your speed needs, check the discussion on the other options here: Recommended way to embed PDF in HTML? and see if the other options fit your requirements.
Approach 1 is inherently dicey due to security reasons