Hi folks, I'll share a solution I found to my version of this problem.
I've been having very high cpu, driving both fans to max on my MBP Mavericks 10.9.5, latest Chrome 45.0.2454.85 (64-bit) when playing some vides from news sites, eg. New York Times. The cpu usage was from Google Chrome Helper, several instances.
My screen resolution was in a funny state, supposedly 1680 x 1050 but my Terminal screen was anti-aliasing the text instead of plain sharp-edge pixels. I used my little menubar helper app SetResX to reset to1680 x 1050. The screen size didn't change, but the Terminal font went back to normal (not anti-aliased) and the Helper usage dropped way down to reasonable levels.
My guess is that the screen was in a funny state and possibly forcing expensive AA (Anti Aliasing) on the video rendering (of the NYT clip). So if you're having huge cpu when playing video, try changing your screen resolution, and change it back to what you want, to "shake up" the rendering settings. If you don't have SetResX, which gives you direct access to all the sizes the Nvidia chip can do, incl. the nice 2800x1880, you cpould just the dumbed-down native options in the Prefernces / Displays panel.
Ciao, Greg E.