Bug: 6569073 Only nativeDestroy and nativeStopGL need to be called on the UI thread, so split up destroyImpl into 3 functions, and only have the native destroy be pushed to the UI thread if necessary. Also make the work that is delayed be static without references to the finalizing WebView to allow it to be fully deleted immediately after finalization. Change-Id: I4e424051e69df0bc409af95ca3f3d2b9e58a6b75