This should remove both CLIENT_LOFI from btoh CL's as well.

Why is this a P1? This sounds like a code cleanup.

There was some part of it that was high priority when I modified the bug, but I rolled that small piece of functionality into a different CL.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4e27eb337661bda1d327121f954418af29c223f7

commit 4e27eb337661bda1d327121f954418af29c223f7
Author: ryansturm <ryansturm@chromium.org>
Date: Tue May 16 16:11:25 2017

Converging the two previews type enums

This CL removes the infobar previews type enum and uses the
previews::PreviewsType enum instead. This also cleans up the code
slightly and introduces a switch statement in infobar_delegate to
enforce that new previews are handled by the infobar link click
appropriately.

BUG= 704335 

Review-Url: https://codereview.chromium.org/2875993002
Cr-Commit-Position: refs/heads/master@{#472122}

[modify] https://crrev.com/4e27eb337661bda1d327121f954418af29c223f7/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_io_data.cc
[modify] https://crrev.com/4e27eb337661bda1d327121f954418af29c223f7/chrome/browser/previews/previews_infobar_delegate.cc
[modify] https://crrev.com/4e27eb337661bda1d327121f954418af29c223f7/chrome/browser/previews/previews_infobar_delegate.h
[modify] https://crrev.com/4e27eb337661bda1d327121f954418af29c223f7/chrome/browser/previews/previews_infobar_delegate_unittest.cc
[modify] https://crrev.com/4e27eb337661bda1d327121f954418af29c223f7/chrome/browser/previews/previews_infobar_tab_helper.cc
[modify] https://crrev.com/4e27eb337661bda1d327121f954418af29c223f7/components/data_reduction_proxy/core/browser/data_reduction_proxy_pingback_client.cc