Revert 180702 "Oilpan: NetworkInformation should be RefCountedGa..."

netinfo/web-worker.html started to crash flakily.

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#showExpectations=true&tests=netinfo%2Fweb-worker.html

> Oilpan: NetworkInformation should be RefCountedGarbageCollected
> 
> This CL just moves NetworkInformation from RefCounted to RefCountedGarbageCollected.
> I tried to ship Oilpan for netinfo/ but realized that there is nothing we can do at this point
> because all objects in netinfo/ inherit from EventTarget or WillBeHeapSupplement.
> 
> BUG=340522
> 
> Review URL: https://codereview.chromium.org/496643002

TBR=haraken@chromium.org

Review URL: https://codereview.chromium.org/481983004

git-svn-id: svn://svn.chromium.org/blink/trunk@180717 bbb929c8-8fbe-4397-9dbb-9b2b20218538