question: public void onExternalNavigation ( String url ) { mSearchPanel . updateTopControlsState ( ) ; if ( ! mDidPromoteSearchNavigation && ! BLACKLISTED_URL . equals ( url ) && ! url . startsWith ( INTENT_URL_PREFIX ) && shouldPromoteSearchNavigation ( ) ) { mDidPromoteSearchNavigation = true ; mSearchPanel . maximizePanelThenPromoteToTab ( StateChangeReason . SERP_NAVIGATION ) ; } }
target:  Called to check if an external navigation is being done and take the appropriate action: Auto-promotes the panel into a separate tab if that's not already being done.