title: Android webview cannot log out of facebook
body: <p>On versions of android below Kitkat I cannot log users out of facebook. I log them in using the manual flow as described here
  <a href="https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow/v2.2" rel="nofollow">https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow/v2.2</a>
  which works flawlessly.
  Logout of my application works but they remained logged into Facebook. I have tried everything to log them out including</p>
  
  <pre><code>webView.clearHistory();
                  webView.clearCache(true);
                  android.webkit.CookieManager.getInstance().removeAllCookie();
                  Log.i("restart","about to restart..");
                  Intent i = getBaseContext().getPackageManager()
                           .getLaunchIntentForPackage( getBaseContext().getPackageName() );
                  i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                  startActivity(i);
                  webView.loadUrl(LOCAL_URL);
  </code></pre>
  
  <p>After the activity restarts they click my applications 'login via Facebook button' and Facebook directs them straight back to me stating they are logged in.</p>
  
  <p>Anyone else had this problem?</p>