question: public final void incrementIdCounterTo ( int id ) { int diff = id - mIdCounter . get ( ) ; if ( diff < 0 ) return ; mIdCounter . addAndGet ( diff ) ; updateSharedPreference ( ) ; }
target:  Ensures the counter is at least as high as the specified value.  The counter should always point to an unused ID (which will be handed out next time a request comes in).  Exposed so that anything externally loading tabs and ids can set enforce new tabs start at the correct id. TODO(dfalcantara): Reduce the visibility of this method once all TabModels are united in how the IDs are assigned (crbug.com/502384).