CPU usage 100% and eating a lot of ram on ubuntu 17.04

Please try taking CPU snapshots once the problem occurs - see https://intellij-support.jetbrains.com/hc/en-us/articles/207241235-Reporting-performance-problems.
Also, I'd suggest excluding all folders dynamically generated by build tools (www/build, dist, etc) from your project (Mark directory as/Excluded). This would reduce the overall code base size and help to avoid project re-indexing while flashing generated files to disk

I have the same problem on mac, the clion consume a lot of cpu (300+%), but when I change the clion.vmoptions and increase the memory to a very large one for example -Xmx6000m, the problem disappear, I think it may be a problem of java.

It happens to me when I do bring up the debugger.  So I am pretty sure it is the debugger itself or its interaction with chrome.  Just doing an npm start doesn't have the issue.   This is definitely something Jetbrains should look into and fix.  Making the nice debugger produce screaming fans isn't good.   Once it starts screaming Just stopping the debugging session doesn't cure it.   Testing further..  Sitting on a breakpoint debugging definitely does it.  Hitting restart in debugger doesn't stop it. From what I am seeing once you start it with a stop at a breakpoint it doesn't go away until you restart webstorm.   But if you error out (traceback in browser) then it does stop screaming.  Curious. 

I hope that helps. 

This is a community forum, troubleshooting performance issues within a forum thread is not the best way to go.
Please try taking CPU snapshots (https://intellij-support.jetbrains.com/hc/en-us/articles/207241235-Reporting-performance-problems) when the issue occurs and submit them along with the logs (Help | Collect Logs and Diagnostic Data) within a support ticket.