Docserver: Update to the latest version of handlebar. Lots of re-syntaxifying.

BUG=293678
R=mkearney@chromium.org

Review URL: https://codereview.chromium.org/61733018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235292 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235292
Remove some pass-thrus on RootWindow API in favor of exposing the RootWindowHost again.

R=sky@chromium.org
http://crbug.com/308843

Review URL: https://codereview.chromium.org/72503002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235293 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235293