Hookup print and save buttons in the out of process PDF plugin

BUG=303491

Review URL: https://codereview.chromium.org/169613005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252884 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 252884