[OfflinePages] Rename PRERENDERING_* result terminology to LOADING_*

[OfflinePages] Rename PRERENDERING_* result terminology to LOADING_*

As we prepare for making new background loader an option over the
prerendering loader, we need to either generalize Offliner and
BackgroundSavePageResult result terminology or create a new set
of results for the new loader. This CL generalizes that terminology.

BUG=670529
Committed: https://crrev.com/926b579529f4f67ab2a22364ac1d9ea1eb29a475
Cr-Commit-Position: refs/heads/master@{#437355}

[dougarnett, 2016-12-08 18:55:25]

The CQ bit was checked by dougarnett@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-08 18:56:16]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[dougarnett, 2016-12-08 19:01:46]

dougarnett@chromium.org changed reviewers:
+ chili@chromium.org, petewil@chromium.org

[Pete Williamson, 2016-12-08 19:20:19]

lgtm

[chili, 2016-12-08 19:30:11]

lgtm

Thanks Doug!

[dougarnett, 2016-12-08 19:56:53]

dougarnett@chromium.org changed reviewers:
+ holte@chromium.org

[dougarnett, 2016-12-08 19:56:53]

Steven, please review this terminology change (generalization) of some existing
histogram enum values.

[Steven Holte, 2016-12-08 20:25:57]

histograms lgtm

[dougarnett, 2016-12-08 20:52:18]

The CQ bit was unchecked by dougarnett@chromium.org

[dougarnett, 2016-12-08 20:52:23]

The CQ bit was checked by dougarnett@chromium.org

[commit-bot: I haz the power, 2016-12-08 20:53:31]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-08 21:41:50]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1481230343520230,
"parent_rev": "1a7252097b2524a3638d225e9df6ebf6abb3ed18", "commit_rev":
"472f67d9c6f4821f809aa3579868a27a6f9b5915"}

[commit-bot: I haz the power, 2016-12-08 21:42:16]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-12-08 21:44:45]

Description was changed from

==========
[OfflinePages] Rename PRERENDERING_* result terminology to LOADING_*

As we prepare for making new background loader an option over the
prerendering loader, we need to either generalize Offliner and
BackgroundSavePageResult result terminology or create a new set
of results for the new loader. This CL generalizes that terminology.

BUG=670529
==========

to

==========
[OfflinePages] Rename PRERENDERING_* result terminology to LOADING_*

As we prepare for making new background loader an option over the
prerendering loader, we need to either generalize Offliner and
BackgroundSavePageResult result terminology or create a new set
of results for the new loader. This CL generalizes that terminology.

BUG=670529

Committed: https://crrev.com/926b579529f4f67ab2a22364ac1d9ea1eb29a475
Cr-Commit-Position: refs/heads/master@{#437355}
==========

[commit-bot: I haz the power, 2016-12-08 21:44:46]

Patchset 2 (id:??) landed as
https://crrev.com/926b579529f4f67ab2a22364ac1d9ea1eb29a475
Cr-Commit-Position: refs/heads/master@{#437355}