fix: Fix compiler error on static use of "this" (#4699)
fix: Fix compiler error on static use of "this" (#4699)

An internal build system failed to compile v4.3.0 due to the use of
static "this". This change fixes it.

Unfortunately, we are already running the latest public compiler
release, so there is no way we could have caught this on GitHub.
shaka-project/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player