Chromium is an open source web browser that strives for a secure, fast and stable web browsing experience for its users. It is the open source project behind Google Chrome.
How to install Chromium:
apt-get update apt-get install chromium chromium-l10n
(chromium-l10n is only used for localization and is optional)
Chromium can view PDFs without any additional extensions (internally using PDFium software library)
http://www.chromium.org/ - Chromium homepage.
http://www.google.com/chrome - Google Chrome homepage.
http://superuser.com/questions/523852 - how to install Chrome Web Store extensions on old Chrome versions such as 6.0.