Well, everyone's downvoting me, but I swear I never noticed this until Yosemite.

Either way, the weird thing is that if you go to the Window menu and hit Task Manager... you can monitor extension CPU usage, etc.

I never had a problem until recently, and yet now I'm seeing red in the Activity Manager due to Chrome. It's bizarre.

You're probably downvoted because it's been pretty widely known that Chrome is a CPU hog on OS X. Checking the energy shaming feature, Chrome is pretty much always in the "Apps Using Significant Energy" section. I did a quick search on "Chrome energy OS X" and found a number of pages that mention it, all of which date back to Mavericks which is the first time energy usage was reported (separate from straight CPU usage).

I only use Chrome if I need to use a site with Flash and I use the "Open Page With" item in Safari's Develop menu to open the appropriate page. Then, I quit once I'm done with it.

You're probably downvoted because it's been pretty widely known that Chrome is a CPU hog on OS X. Checking the energy shaming feature, Chrome is pretty much always in the "Apps Using Significant Energy" section. I did a quick search on "Chrome energy OS X" and found a number of pages that mention it, all of which date back to Mavericks which is the first time energy usage was reported (separate from straight CPU usage).

Same, often a few with one crashed.