Update license whitelist after NaCL docs

Add native_client_sdk/doc_generated/rest-devsite-examples.html to
whitelist, which was added in r246665.

BUG=
R=akalin@chromium.org

Review URL: https://codereview.chromium.org/143073007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246668 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246668