public void setDrawerIndicatorEnabled(boolean enabled) {
        if (mActionBarHelper == null) {
            throw new IllegalStateException("setupUpIndicator(Activity) has not been called");
        }

        mDrawerIndicatorEnabled = enabled;
        if (enabled) {
            mActionBarHelper.setActionBarUpIndicator(mSlideDrawable,
                    isMenuVisible() ? mDrawerOpenContentDesc : mDrawerClosedContentDesc);
        } else {
            mActionBarHelper.setActionBarUpIndicator(mThemeUpIndicator, 0);
        }
    }
Sets whether the drawer indicator should be enabled. {@link #setupUpIndicator(android.app.Activity)} must be
called first.

@param enabled Whether the drawer indicator should enabled.
menudrawer/src/net/simonvt/menudrawer/MenuDrawer.java