Edits the user picture for the test user.
function saveUserPicture($image) {
$edit = array(
'files[user_picture_und_0]' => drupal_realpath($image->uri),
);
$this
->drupalPost('user/' . $this->web_user->uid . '/edit', $edit, t('Save'));
// Load actual user data from database.
$account = user_load($this->web_user->uid, TRUE);
return file_load($account->user_picture[LANGUAGE_NOT_SPECIFIED][0]['fid']);
}