Revert 219911 "Pepper: Move FileRef to the "new" resource proxy."

Revert 219911 "Pepper: Move FileRef to the "new" resource proxy."

There have been multiple test failures among users of the CRX filesystem, which
is not adequately tested by existing tests. I'm not sure at all what's broken,
but I guess I'll have to do manual testing to sort it out.

> 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
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=218305
> 
> Review URL: https://chromiumcodereview.appspot.com/21966004

TBR=teravest@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=220165

[teravest, 2013-08-29 02:15:51]

Committed patchset #1 manually as r220165.