Add missing @private annotations and goog.requires
Add missing @private annotations and goog.requires

Change-Id: Ieacf51e9c82eb1c5fa72d4d8594055a785e829ef

tvoli/shaka-player,TheModMaker/shaka-player,shaka-project/shaka-player,TheModMaker/shaka-player,tvoli/shaka-player,tvoli/shaka-player,TheModMaker/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,TheModMaker/shaka-player