Apple - Set Chrome to open PDF rather than download them

FYI This answer is outdated and no longer relevant:

Go to chrome://extensions in the address bar, then find and enable Chromium PDF Viewer.

This will tell Chrome to use its built-in PDF viewer instead of downloading. After this is enabled, to download PDFs, just press command+S.

You will have to teach your Chrome how to Preview PDF's

For that you need to install a PDF preview "add on" in Chrome.

Automatically previews pdfs, powerpoint presentations, and other documents in Google Docs Viewer.

Or you can try this : You can normally open PDFs automatically in Chrome by clicking on the file you want to see.

If your PDFs are downloading instead of opening automatically in Chrome, Chrome PDF viewer could be turned off.

On your computer, open Chrome. At the top right, click More Settings. At the bottom, click Show advanced settings. Under “Privacy”, click Content settings. Under “PDF Documents," check the box next to "Open PDF files in the default PDF viewer application.” (Uncheck this box if you want PDFs to open automatically when you click them.)

In Google Chrome go to Settings. Scroll to the bottom of the page and click on the hyperlink for Show Advanced Settings. From there scroll down until you find the "Download" section. Uncheck the box where it asks where to save each file before downloading. Close Chrome and reopen. You should now be able to have the PDF open without prompting to save it.