Horizontal menu inflater on long click for web view

In whichever activity is hosting your WebView, override onActionModeStarted(), manipulate the menu items, and assign listeners to each. An example:

@Override
public void onActionModeStarted(ActionMode mode) {
    super.onActionModeStarted(mode);

    MenuInflater menuInflater = mode.getMenuInflater();
    Menu menu = mode.getMenu();

    menu.clear();
    menuInflater.inflate(R.menu.menu_custom, menu);

    menu.findItem(R.id.custom_one).setOnMenuItemClickListener(new ToastMenuItemListener(this, mode, "One!"));
    menu.findItem(R.id.custom_two).setOnMenuItemClickListener(new ToastMenuItemListener(this, mode, "Two!"));
    menu.findItem(R.id.custom_three).setOnMenuItemClickListener(new ToastMenuItemListener(this, mode, "Three!"));
}

private static class ToastMenuItemListener implements MenuItem.OnMenuItemClickListener {

    private final Context context;
    private final ActionMode actionMode;
    private final String text;

    private ToastMenuItemListener(Context context, ActionMode actionMode, String text) {
        this.context = context;
        this.actionMode = actionMode;
        this.text = text;
    }

    @Override
    public boolean onMenuItemClick(MenuItem item) {
        Toast.makeText(context, text, Toast.LENGTH_SHORT).show();
        actionMode.finish();
        return true;
    }
}