return cached asset

ExoPlayer: Don't stop playback when detaching

A number of people run into SurfaceView layering issues. It seems better to default to the more compatible option and let people reconfigure if they need the extra SurfaceView performance.

Update to ExoPlayer 2.9.0 & document version 4.0.0 breaking changes

Support RN 0.57 w/ gradle 3

Enhanced Fullscreen options for iOS

react-native-dom: DASH & HLS support, autoplay detection

orientation; added tvOS target to examples/basic/ios project

Fix "progressInterval"  to "progressUpdateInterval" in README

Minor cleanups to onExternalPlaybackChange

introducing onExternalPlaybackChange