Remove use of libcros from InputMethodLibrary.

BUG=chromium-os:16238
TEST==confirm that input methods work as before on the netbook. Also confirm that the chrome builds and works on the desktop as before.

Review URL: http://codereview.chromium.org/7003086

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@89142 0039d316-1c4b-4281-b951-d872f2087c98
   virtual void RemoveObserver(Observer* observer) {}

   virtual void RemoveObserver(Observer* observer) {}
