When you click on a link to a PDF file, Chrome no longer opens the file using the Adobe Reader plug-in. Instead, Google Chrome uses a basic PDF viewer that lacks many useful features like pagination and bookmarks.
"PDF files will render as seamlessly as HTML web pages, and basic interactions will be no different than the same interactions with web pages (for example, zooming and searching will work as users expect). PDF rendering quality is still a work in progress, and we will improve it substantially before releasing it to the beta and stable channels. To further protect users, PDF functionality will be contained within the security sandbox Chrome uses for web page rendering. Users will automatically receive the latest version of Chrome's PDF support; they won't have to worry about manually updating any plug-ins or programs," explains Google.
This is especially useful for Chrome OS users, who won't be able to install PDF viewers like Adobe Reader or Evince. Instead of relying on Google Docs Viewer, Chrome will be able to display PDF files faster, especially if they're saved locally.
{ Thanks, Arpit. }