Delete obsolete prerender experiment code

Delete obsolete prerender experiment code

This experiment is deprecated since 2012 and the code can now be
removed.

TBR=fgorski

Committed: https://crrev.com/43d1d1af21be4793f2a24e36f321a140138d0f3e
Cr-Commit-Position: refs/heads/master@{#434513}

[droger, 2016-11-25 13:09:50]

Description was changed from

==========
Delete obsolete prerender experiment code
==========

to

==========
Delete obsolete prerender experiment code

This experiment is deprecated since 2012 and the code can now be
removed.
Only PRERENDER_MODE_EXPERIMENT_NO_USE_GROUP is kept, since we
are going to implement a similar experiment and we can re-use this
enum value.
==========

[droger, 2016-11-25 13:09:51]

droger@chromium.org changed reviewers:
+ mattcary@chromium.org, pasko@chromium.org

[droger, 2016-11-25 13:12:42]

https://codereview.chromium.org/2527363002/diff/1/chrome/browser/prerender/pr...
File chrome/browser/prerender/prerender_manager.h (left):

https://codereview.chromium.org/2527363002/diff/1/chrome/browser/prerender/pr...
chrome/browser/prerender/prerender_manager.h:83: // NOTE: New values need to be
appended, since they are used in histograms.
The histogram no longer exist in the code, but it still exists in histogram.xml,
marked as deprecated since 2012.
I did not delete the histogram from histogram.xml, so that the data remains
accessible from UMA queries, but we could consider deleting it maybe.

[mattcary, 2016-11-25 13:21:07]

lgtm

Yay for deleting code!

https://codereview.chromium.org/2527363002/diff/1/chrome/browser/prerender/pr...
File chrome/browser/prerender/prerender_manager.h (left):

https://codereview.chromium.org/2527363002/diff/1/chrome/browser/prerender/pr...
chrome/browser/prerender/prerender_manager.h:83: // NOTE: New values need to be
appended, since they are used in histograms.
On 2016/11/25 13:12:42, droger wrote:
> The histogram no longer exist in the code, but it still exists in
histogram.xml,
> marked as deprecated since 2012.
> I did not delete the histogram from histogram.xml, so that the data remains
> accessible from UMA queries, but we could consider deleting it maybe.

Does this change does mean that is will be nearly impossible to interpret the
old histograms, as the enum reference is gone, or does  uma save the enum value
names?

[droger, 2016-11-25 13:44:36]

https://codereview.chromium.org/2527363002/diff/1/chrome/browser/prerender/pr...
File chrome/browser/prerender/prerender_manager.h (left):

https://codereview.chromium.org/2527363002/diff/1/chrome/browser/prerender/pr...
chrome/browser/prerender/prerender_manager.h:83: // NOTE: New values need to be
appended, since they are used in histograms.
On 2016/11/25 13:21:07, mattcary wrote:
> On 2016/11/25 13:12:42, droger wrote:
> > The histogram no longer exist in the code, but it still exists in
> histogram.xml,
> > marked as deprecated since 2012.
> > I did not delete the histogram from histogram.xml, so that the data remains
> > accessible from UMA queries, but we could consider deleting it maybe.
> 
> Does this change does mean that is will be nearly impossible to interpret the
> old histograms, as the enum reference is gone, or does  uma save the enum
value
> names?

Looking at histogram in UMA does not use the enum from C++, it has it's own enum
in histograms.xml (which is basically a copy of this one).

The C++ enum was only used to upload data from the client, but in this case, it
is not even used at all currently since the histogram is already deleted from
the C++ code.

[droger, 2016-11-25 13:58:54]

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

[commit-bot: I haz the power, 2016-11-25 13:59:10]

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

[droger, 2016-11-25 14:01:23]

Description was changed from

==========
Delete obsolete prerender experiment code

This experiment is deprecated since 2012 and the code can now be
removed.
Only PRERENDER_MODE_EXPERIMENT_NO_USE_GROUP is kept, since we
are going to implement a similar experiment and we can re-use this
enum value.
==========

to

==========
Delete obsolete prerender experiment code

This experiment is deprecated since 2012 and the code can now be
removed.
==========

[droger, 2016-11-25 14:05:37]

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

[commit-bot: I haz the power, 2016-11-25 14:05:47]

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

[pasko, 2016-11-25 14:19:07]

lgtm with the obvious fix for Android:

chrome/browser/android/offline_pages/prerender_adapter.cc:29

[pasko, 2016-11-25 14:19:31]

forgot to say: yay! less code! thanks!

https://codereview.chromium.org/2527363002/diff/1/chrome/browser/prerender/pr...
File chrome/browser/prerender/prerender_manager.h (left):

https://codereview.chromium.org/2527363002/diff/1/chrome/browser/prerender/pr...
chrome/browser/prerender/prerender_manager.h:83: // NOTE: New values need to be
appended, since they are used in histograms.
On 2016/11/25 13:44:36, droger wrote:
> On 2016/11/25 13:21:07, mattcary wrote:
> > On 2016/11/25 13:12:42, droger wrote:
> > > The histogram no longer exist in the code, but it still exists in
> > histogram.xml,
> > > marked as deprecated since 2012.
> > > I did not delete the histogram from histogram.xml, so that the data
remains
> > > accessible from UMA queries, but we could consider deleting it maybe.
> > 
> > Does this change does mean that is will be nearly impossible to interpret
the
> > old histograms, as the enum reference is gone, or does  uma save the enum
> value
> > names?
> 
> Looking at histogram in UMA does not use the enum from C++, it has it's own
enum
> in histograms.xml (which is basically a copy of this one).
> 
> The C++ enum was only used to upload data from the client, but in this case,
it
> is not even used at all currently since the histogram is already deleted from
> the C++ code.

yeah, UMA dashbnoard does not know about enums in C++, it renders from the
uploaded ints/buckets and histograms.xml.

[commit-bot: I haz the power, 2016-11-25 14:22:23]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-25 14:22:24]

Dry run: Try jobs failed on following builders:
  android_n5x_swarming_rel on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_n5x_...)

[droger, 2016-11-25 14:28:25]

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

[commit-bot: I haz the power, 2016-11-25 14:28:36]

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

[droger, 2016-11-25 14:54:12]

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

[commit-bot: I haz the power, 2016-11-25 14:54:18]

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

[droger, 2016-11-25 14:55:16]

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

[droger, 2016-11-25 14:55:27]

Patchset #3 (id:40001) has been deleted

[commit-bot: I haz the power, 2016-11-25 14:55:29]

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

[droger, 2016-11-25 14:55:34]

Patchset #3 (id:60001) has been deleted

[commit-bot: I haz the power, 2016-11-25 15:46:57]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-25 15:46:57]

Dry run: This issue passed the CQ dry run.

[droger, 2016-11-25 15:56:57]

droger@chromium.org changed reviewers:
+ fgorski@chromium.org

[droger, 2016-11-25 15:56:58]

TBR fgorski for chrome/browser/android/offline_pages/prerender_adapter.cc
(simple function rename without behavior change).

[droger, 2016-11-25 15:57:09]

Description was changed from

==========
Delete obsolete prerender experiment code

This experiment is deprecated since 2012 and the code can now be
removed.
==========

to

==========
Delete obsolete prerender experiment code

This experiment is deprecated since 2012 and the code can now be
removed.

TBR=fgorski
==========

[droger, 2016-11-25 15:57:18]

The CQ bit was checked by droger@chromium.org

[droger, 2016-11-25 15:57:18]

The patchset sent to the CQ was uploaded after l-g-t-m from
mattcary@chromium.org, pasko@chromium.org
Link to the patchset: https://codereview.chromium.org/2527363002/#ps80001
(title: "Fix android compilation")

[commit-bot: I haz the power, 2016-11-25 15:57:37]

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, 2016-11-25 16:01:13]

CQ is committing da patch.

Bot data: {"patchset_id": 80001, "attempt_start_ts": 1480089438257180,
"parent_rev": "acadb3bd5efea819b0205fcee54f75d8b53c3b7f", "commit_rev":
"5ebbaac30f261469f3b2475f8457e762b3363eae"}

[commit-bot: I haz the power, 2016-11-25 16:01:38]

Description was changed from

==========
Delete obsolete prerender experiment code

This experiment is deprecated since 2012 and the code can now be
removed.

TBR=fgorski
==========

to

==========
Delete obsolete prerender experiment code

This experiment is deprecated since 2012 and the code can now be
removed.

TBR=fgorski
==========

[commit-bot: I haz the power, 2016-11-25 16:01:39]

Committed patchset #3 (id:80001)

[commit-bot: I haz the power, 2016-11-25 16:04:45]

Description was changed from

==========
Delete obsolete prerender experiment code

This experiment is deprecated since 2012 and the code can now be
removed.

TBR=fgorski
==========

to

==========
Delete obsolete prerender experiment code

This experiment is deprecated since 2012 and the code can now be
removed.

TBR=fgorski

Committed: https://crrev.com/43d1d1af21be4793f2a24e36f321a140138d0f3e
Cr-Commit-Position: refs/heads/master@{#434513}
==========

[commit-bot: I haz the power, 2016-11-25 16:04:47]

Patchset 3 (id:??) landed as
https://crrev.com/43d1d1af21be4793f2a24e36f321a140138d0f3e
Cr-Commit-Position: refs/heads/master@{#434513}