Revert 247578 "Add the viewer toolbar to the PDF extension."

> Add the viewer toolbar to the PDF extension.
> 
> BUG=303491
> R=arv@chromium.org, ganetsky@chromium.org
> 
> Review URL: https://codereview.chromium.org/110723007

TBR=raymes@google.com

Review URL: https://codereview.chromium.org/135183012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247588 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 247588