Please see the many, many, many other posts on this issue.
Flash is never going to happen on webOS (or Samsung Tizen), Flash is as another poster put it 'already in its coffin'.
Adobe has officially said it is killing Flash in 2020, no one in their right mind at LG is going to waste time and money supporting a hideously out-dated piece of buggy bloaty security nightmare piece of software that has been superseded by other better, slimmer, securer software.
If the site you want to watch uses Flash contact the web-master and invite them in to the 21st century... Hell they could even use Adobe Muse to create the site. Oh hold on Adobe has just killed that off as well. Do you see the theme on Adobe web products going on here?