Whenever I click on a link which contain a PDF file, Chromium automatically downloads the file. Instead, I would like to open it for my viewing rather than downloading it.
How can I achieve this?
You have two main options:
Install Docs PDF/PowerPoint Viewer in chromium.
It will let you open pdf file in browser. You can also download those file if you wish.
By clicking on a link for a supported document format you'll be taken to the Google Docs Viewer. On the options page you can also disable any file formats you don't want to use the Viewer for.