Revert 218305 "Pepper: Move FileRef to the "new" resource proxy."

Revert 218305 "Pepper: Move FileRef to the "new" resource proxy."

This change is being reverted because it was causing some crashes for an
application that I haven't been able to debug yet.

> Pepper: Move FileRef to the "new" resource proxy.
> 
> This change moves the FileRef implementation from the previous one in the "old"
> resource model (ppb_file_ref_impl.cc) to the "new" resource model
> (pepper_file_ref_host.cc), and from the renderer to the browser.
> 
> As many as possible of the supporting changes were split off to other changes
> to minimize the size of this change. Unfortunately, a lot of changes for
> URLLoader had to be rolled into this change.
> 
> The data structures for CreateInfo have changed, and all users of FileRef have
> to be moved over, which is what causes this change to be so large.
> 
> TBR=dmichael@chromium.org, jschuh@chromium.org, yzshen@chromium.org
> BUG=225441
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=216744
> 
> Review URL: https://chromiumcodereview.appspot.com/21966004

TBR=teravest@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=218544

[teravest, 2013-08-20 20:09:14]

Committed patchset #1 manually as r218544.