Confirmed, in chromium 60.0.3112.113 ldd was able to locate libffmpeg.so:
$ ldd /usr/lib/chromium-browser/chromium-browser | grep ffmpeg libffmpeg.so => /usr/lib/chromium-browser/./libffmpeg.so (0x00007fec793cc000)
In chromium 61.0.3163.79, it can't locate it:
$ ldd /usr/lib/chromium-browser/chromium-browser | grep ffmpeg libffmpeg.so => not found
Confirmed, in chromium 60.0.3112.113 ldd was able to locate libffmpeg.so:
$ ldd /usr/lib/ chromium- browser/ chromium- browser | grep ffmpeg
libffmpeg. so => /usr/lib/ chromium- browser/ ./libffmpeg. so (0x00007fec793c c000)
In chromium 61.0.3163.79, it can't locate it:
$ ldd /usr/lib/ chromium- browser/ chromium- browser | grep ffmpeg
libffmpeg. so => not found