Porting changes on DevSite back to Chromium.
Replacing auto-generated left-nav with a manual left-nav for now.

R=binji@chromium.org

Review URL: https://codereview.chromium.org/123773002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243114 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243114