Revert 276494 "Revert 275655 "Redirect HTML resource bytes direc..."

Revert 276494 "Revert 275655 "Redirect HTML resource bytes direc..."

Relanding with two fixes: Check that Blink hasn't shut down the background (parser) thread before posting tasks to it, and only attach the ThreadedDataProvider if we have a shared memory handle available (fixes a crash when loading FTP listings)

> Revert 275655 "Redirect HTML resource bytes directly to parser t..."
>
> > Redirect HTML resource bytes directly to parser thread (Chrome side)
> >
> > Blink side: https://codereview.chromium.org/100563004/
> >
> > Note: This can't land until the Blink-side has landed.
> >
> > R=jamesr@chromium.org,jam@chromium.org
> > BUG=277886
> >
> > Review URL: https://codereview.chromium.org/109283006
>
> TBR=oysteine@chromium.org
>
> Review URL: https://codereview.chromium.org/326403005

TBR=darin@chromium.org

Review URL: https://codereview.chromium.org/334813004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@277551 0039d316-1c4b-4281-b951-d872f2087c98