Delete long-expired GlobalSdch field trial.

Delete long-expired GlobalSdch field trial.

BUG=229940
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=202728

[Alexei Svitkine (slow), 2013-05-27 19:31:28]

Hey Jim,

I'm not sure if you had planned to revive this field trial, but it's been
expired for a year now.

If you're not planning to revive it, here's a CL that delete the code.

[jar (doing other things), 2013-05-28 18:35:02]

I'm ok with ripping out the field trial.  See suggestion below about how to do
so.

https://codereview.chromium.org/16115002/diff/1/chrome/renderer/page_load_his...
File chrome/renderer/page_load_histograms.cc (right):

https://codereview.chromium.org/16115002/diff/1/chrome/renderer/page_load_his...
chrome/renderer/page_load_histograms.cc:423:
PLT_HISTOGRAM("PLT.BeginToFinish_NormalLoad",
You'll notice that this exact histogram is already gathered on line 364.

This whole section, starting at line 418, and ending at line 445, is *only* done
*IF* we have a field trial.  IF we don't have a field trial, then we don't do
the MakeName combination.

Bottom line: You should remove all code from line 414 to line 445 when you rip
out the field trial.

The pattern seen here is VERY common, and consists of:

a) Check to see if there is a histogram of the given name.
b) If there is one, then record some special variants on *existing* histograms,
using the MakeName() helper.

[Alexei Svitkine (slow), 2013-05-28 18:47:44]

address comment

[Alexei Svitkine (slow), 2013-05-28 18:48:58]

https://codereview.chromium.org/16115002/diff/1/chrome/renderer/page_load_his...
File chrome/renderer/page_load_histograms.cc (right):

https://codereview.chromium.org/16115002/diff/1/chrome/renderer/page_load_his...
chrome/renderer/page_load_histograms.cc:423:
PLT_HISTOGRAM("PLT.BeginToFinish_NormalLoad",
On 2013/05/28 18:35:02, jar wrote:
> You'll notice that this exact histogram is already gathered on line 364.
> 
> This whole section, starting at line 418, and ending at line 445, is *only*
done
> *IF* we have a field trial.  IF we don't have a field trial, then we don't do
> the MakeName combination.
> 
> Bottom line: You should remove all code from line 414 to line 445 when you rip
> out the field trial.
> 
> The pattern seen here is VERY common, and consists of:
> 
> a) Check to see if there is a histogram of the given name.
> b) If there is one, then record some special variants on *existing*
histograms,
> using the MakeName() helper.

Ah, you're absolutely right! Done.

[jar (doing other things), 2013-05-28 18:51:21]

lgtm

[commit-bot: I haz the power, 2013-05-28 18:54:40]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/asvitkine@chromium.org/16115002/16001

[commit-bot: I haz the power, 2013-05-28 19:02:35]

Retried try job too often on chromium_presubmit for step(s) presubmit
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=chromium_p...

[commit-bot: I haz the power, 2013-05-28 19:04:01]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/asvitkine@chromium.org/16115002/16001

[Alexei Svitkine (slow), 2013-05-28 19:07:25]

+thakis for owners

[Nico, 2013-05-28 19:13:18]

lgtm stamp

what were the results of this field trial? can we finally delete the sdch code?

[commit-bot: I haz the power, 2013-05-28 19:16:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/asvitkine@chromium.org/16115002/16001

[commit-bot: I haz the power, 2013-05-29 01:06:40]

Change committed as 202728