Extend silk benchmark of navigation drawer

This CL adds a second test case for inbox_app's navigation drawer that toggles
the drawer open and closed using the toolbar button.

R=nduca@chromium.org
BUG=332439

Review URL: https://codereview.chromium.org/130433003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243956 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243956