Remove unused functions: searchMenu{NoRecent,Recent,ClearRecent}SearchesText().

BUG=none
TEST=none; no behavior changes.

Review URL: https://chromiumcodereview.appspot.com/25193002

git-svn-id: svn://svn.chromium.org/blink/trunk@158506 bbb929c8-8fbe-4397-9dbb-9b2b20218538