Remove unused DRP code for migrating prefs

Remove unused DRP code for migrating prefs

Remove the data reduction proxy code that migrates the
compression prefs. Also, remove the code that enables
compression stats logging without a valid
DataReductionProxyStore. Both of these are currently
unreachable.

BUG=660136
Committed: https://crrev.com/7839ed7cd5aae2d76abfeccef3fd2867a6b4e864
Cr-Commit-Position: refs/heads/master@{#428185}

[tbansal1, 2016-10-26 07:40:56]

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

[commit-bot: I haz the power, 2016-10-26 07:41:06]

Dry run: 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, 2016-10-26 08:41:11]

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

[commit-bot: I haz the power, 2016-10-26 08:41:11]

Dry run: This issue passed the CQ dry run.

[tbansal1, 2016-10-26 16:51:05]

tbansal@chromium.org changed reviewers:
+ ryansturm@chromium.org

[tbansal1, 2016-10-26 16:51:05]

ptal. I am going to file a bug soon.

[RyanSturm, 2016-10-26 18:28:19]

Seems fine, can you add bengr@ instead as he was the one that wrote the TODO to
remove it. He might have more context here on why it was necessary originally.

[tbansal1, 2016-10-26 18:33:48]

tbansal@chromium.org changed reviewers:
+ bengr@chromium.org

[tbansal1, 2016-10-26 18:33:48]

bengr: ptal. thanks.

[bengr, 2016-10-27 18:28:37]

lgtm

https://codereview.chromium.org/2447013003/diff/1/components/data_reduction_p...
File components/data_reduction_proxy/core/browser/data_reduction_proxy_prefs.h
(left):

https://codereview.chromium.org/2447013003/diff/1/components/data_reduction_p...
components/data_reduction_proxy/core/browser/data_reduction_proxy_prefs.h:35:
void MigrateStatisticsPrefs(PrefService* src, PrefService* dest);
Compression history data will be lost for users who upgrade from <M40. This CL
makes sense now, as this is a tiny fraction of the population.

[tbansal1, 2016-10-27 20:12:46]

https://codereview.chromium.org/2447013003/diff/1/components/data_reduction_p...
File components/data_reduction_proxy/core/browser/data_reduction_proxy_prefs.h
(left):

https://codereview.chromium.org/2447013003/diff/1/components/data_reduction_p...
components/data_reduction_proxy/core/browser/data_reduction_proxy_prefs.h:35:
void MigrateStatisticsPrefs(PrefService* src, PrefService* dest);
On 2016/10/27 18:28:37, bengr wrote:
> Compression history data will be lost for users who upgrade from <M40. This CL
> makes sense now, as this is a tiny fraction of the population.

This is currently an unreachable function. I am not sure when the call was
removed.

[tbansal1, 2016-10-27 20:22:23]

https://codereview.chromium.org/2447013003/diff/1/components/data_reduction_p...
File components/data_reduction_proxy/core/browser/data_reduction_proxy_prefs.h
(left):

https://codereview.chromium.org/2447013003/diff/1/components/data_reduction_p...
components/data_reduction_proxy/core/browser/data_reduction_proxy_prefs.h:35:
void MigrateStatisticsPrefs(PrefService* src, PrefService* dest);
On 2016/10/27 20:12:45, tbansal1 wrote:
> On 2016/10/27 18:28:37, bengr wrote:
> > Compression history data will be lost for users who upgrade from <M40. This
CL
> > makes sense now, as this is a tiny fraction of the population.
> 
> This is currently an unreachable function. I am not sure when the call was
> removed.

Dug more.

It used to be called in chrome/browser/profiles/profile_impl.cc:
https://codereview.chromium.org/652743004/diff/170001/chrome/browser/profiles...

But, it seems it was accidentally removed 3 month later:
https://codereview.chromium.org/778463002/

[tbansal1, 2016-10-27 20:24:37]

Description was changed from

==========
Remove unused DRP code

BUG=
==========

to

==========
Remove unused DRP code for migrating prefs

Remove the data reduction proxy code that migrates the 
compression prefs. Also, remove the code that enables 
compression stats logging without a valid 
DataReductionProxyStore. Both of these are currently 
unreachable.

BUG=660136
==========

[tbansal1, 2016-10-27 20:24:40]

The CQ bit was checked by tbansal@chromium.org

[commit-bot: I haz the power, 2016-10-27 20:25:41]

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, 2016-10-27 23:00:24]

Description was changed from

==========
Remove unused DRP code for migrating prefs

Remove the data reduction proxy code that migrates the 
compression prefs. Also, remove the code that enables 
compression stats logging without a valid 
DataReductionProxyStore. Both of these are currently 
unreachable.

BUG=660136
==========

to

==========
Remove unused DRP code for migrating prefs

Remove the data reduction proxy code that migrates the 
compression prefs. Also, remove the code that enables 
compression stats logging without a valid 
DataReductionProxyStore. Both of these are currently 
unreachable.

BUG=660136
==========

[commit-bot: I haz the power, 2016-10-27 23:00:25]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-27 23:04:41]

Description was changed from

==========
Remove unused DRP code for migrating prefs

Remove the data reduction proxy code that migrates the 
compression prefs. Also, remove the code that enables 
compression stats logging without a valid 
DataReductionProxyStore. Both of these are currently 
unreachable.

BUG=660136
==========

to

==========
Remove unused DRP code for migrating prefs

Remove the data reduction proxy code that migrates the
compression prefs. Also, remove the code that enables
compression stats logging without a valid
DataReductionProxyStore. Both of these are currently
unreachable.

BUG=660136

Committed: https://crrev.com/7839ed7cd5aae2d76abfeccef3fd2867a6b4e864
Cr-Commit-Position: refs/heads/master@{#428185}
==========

[commit-bot: I haz the power, 2016-10-27 23:04:42]

Patchset 1 (id:??) landed as
https://crrev.com/7839ed7cd5aae2d76abfeccef3fd2867a6b4e864
Cr-Commit-Position: refs/heads/master@{#428185}