Remove FrameSniffer since it's not used anymore after r230040.

BUG=306569
R=avi@chromium.org, armansito@chromium.org

Review URL: https://codereview.chromium.org/35433002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230733 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230733