If you use Windows you can go to menu Edit -> Preferences, choose General category and "Select Default .PDF Handler" at the bottom of he Window.
Select Default PDF Handler (Windows only)
Specifies which application, Reader or Acrobat, is used to open PDFs. This setting applies if you have both Acrobat and Reader installed on your computer. In Windows 7 or earlier, a browser uses this setting only if it is using the Adobe plug-in or add-on for viewing PDF files. In Windows 8, this setting controls which application is the default PDF application for your system, including in your browser. Windows 8 prompts you to allow this change before applying it to your system. Once set, Windows 8 also uses the selected PDF application for tasks related to PDF files, such as previewing, displaying thumbnails, and providing file information.
To display PDF within Google Chrome, take a look at: http://helpx.adobe.com/acrobat/using/display-pdf-browser-acrobat-xi.html