I'm not sure how other emacs users do this, but I use `projectile-grep` to grep for symbols in a project all the time. In the spacemacs this is bound to `SPC g s p`.
I use helm-ag for the same purpose, but it still generally isn't as fast as CMD-b in webstorm. I should hook up something to do helm-ag for the symbol under point...
Projectile-grep is awesome. I use it too. Although I swapped out grep for platinum-searcher for freaky fast results (at the loss of certain regex features)