Revert of DevTools: Refactor the way workspace is populated. (https://chromiumcodereview.appspot.com/231233002/)

Reason for revert:
.

Original issue's description:
> DevTools: Refactor the way workspace is populated.
> 
> In particular:
>  - Renamed workspace providers to workspace bindings.
>  - Migrated ProjectDelegate events to ProjectStore methods.
> 
> R=pfeldman
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=171250

TBR=pfeldman@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/232053006

git-svn-id: svn://svn.chromium.org/blink/trunk@171288 bbb929c8-8fbe-4397-9dbb-9b2b20218538