After chatting offline with Zach:

For dev + canary and beta, let's show each experiment to 10% of users. In addition to that we should have a corresponding 10% control group.

Based on the beta experiment results, we will assess what proportion of users in production will see each experiment.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2364a394e98147f92f80ddeb5a1c56abbb547951

commit 2364a394e98147f92f80ddeb5a1c56abbb547951
Author: ftang <ftang@chromium.org>
Date: Thu Jun 30 18:41:52 2016

add experimental param to control the triggering threshold to default Always Translate checked

BUG= 622854 

Review-Url: https://codereview.chromium.org/2090283002
Cr-Commit-Position: refs/heads/master@{#403232}

[modify] https://crrev.com/2364a394e98147f92f80ddeb5a1c56abbb547951/components/translate/DEPS
[modify] https://crrev.com/2364a394e98147f92f80ddeb5a1c56abbb547951/components/translate/core/browser/BUILD.gn
[modify] https://crrev.com/2364a394e98147f92f80ddeb5a1c56abbb547951/components/translate/core/browser/translate_prefs.cc
[modify] https://crrev.com/2364a394e98147f92f80ddeb5a1c56abbb547951/components/translate/core/browser/translate_prefs.h
[modify] https://crrev.com/2364a394e98147f92f80ddeb5a1c56abbb547951/components/translate/core/browser/translate_ui_delegate.cc
[modify] https://crrev.com/2364a394e98147f92f80ddeb5a1c56abbb547951/components/translate/core/browser/translate_ui_delegate_unittest.cc

[Automated comment] DEPS changes referenced in bugdroid comments, needs manual review.

Before we approve merge to M52, Could you please confirm whether this change is baked/verified in Canary and safe to merge?

Trying to verify the CL from C#4 on the latest canary(54.0.2789.0) on Windows-7 and below are the observations:

Test URL: baidu.com
OS platform: Windows-7

Chrome version: 53.0.2782.0(Without the CL from C#4) 
1. First land: Always translate unchecked
2. 1st Translation>Translate: Always translate unchecked
3. Show Original> Always translate--unchecked
4. 2nd translation-Translate> Always translate-unchecked
5. 3rd translation-Always translate-unchecked
6. 5th translation-Always translate-unchecked
7. Always translate never checked by default

Chrome version: 54.0.2789.0(With the CL from C#4))
1. First land: Always translate unchecked
2. 1st translation>Translate: Always translate unchecked
3. Show Original> Always translate--unchecked
4. 2nd translation-Translate> Always translate- unchecked
5. 3rd translation-Always translate unchecked
6. 5th translation-Always translate unchecked
7. Always translate never checked by default

>As per C#1 the experiment looks to be available to 10% of users as of now.

ftang@: Could you please review the above test result and confirm if anything missed here. Please let us know if any precondition required to enter into the above experiment and test this. 

Thank you!

The change will make the "Always Translate" never checked by default, unless it is part of some experimental which has different parameter. So the behavior is correct.

Thank you Amit for verifying it in the Canary.

@Di, can you please approve the Merge in to M52 branch ?

Approving merge to M52.

ftang@, can you please merge in to M52 branch by EOD so that it gets picked up for the upcoming beta promotion scheduled next week.

groby did that for me before but she is on vacation now till Monday. I do not have committer right and do not know how to merge it into M52. zkoch- could you find someone do that for me?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9db11679b5eb2b9a9d5df3a1ae4de65212a3eb84

commit 9db11679b5eb2b9a9d5df3a1ae4de65212a3eb84
Author: Jungshik Shin <jshin@chromium.org>
Date: Fri Jul 08 23:33:10 2016

[Merge M52] add experimental param to control the triggering threshold to default Always Translate checked

BUG= 622854 

Review-Url: https://codereview.chromium.org/2090283002
Cr-Commit-Position: refs/heads/master@{#403232}
(cherry picked from commit 2364a394e98147f92f80ddeb5a1c56abbb547951)

Review URL: https://codereview.chromium.org/2135813002 .

Cr-Commit-Position: refs/branch-heads/2743@{#601}
Cr-Branched-From: 2b3ae3b8090361f8af5a611712fc1a5ab2de53cb-refs/heads/master@{#394939}

[modify] https://crrev.com/9db11679b5eb2b9a9d5df3a1ae4de65212a3eb84/components/translate/DEPS
[modify] https://crrev.com/9db11679b5eb2b9a9d5df3a1ae4de65212a3eb84/components/translate/core/browser/BUILD.gn
[modify] https://crrev.com/9db11679b5eb2b9a9d5df3a1ae4de65212a3eb84/components/translate/core/browser/translate_prefs.cc
[modify] https://crrev.com/9db11679b5eb2b9a9d5df3a1ae4de65212a3eb84/components/translate/core/browser/translate_prefs.h
[modify] https://crrev.com/9db11679b5eb2b9a9d5df3a1ae4de65212a3eb84/components/translate/core/browser/translate_ui_delegate.cc
[modify] https://crrev.com/9db11679b5eb2b9a9d5df3a1ae4de65212a3eb84/components/translate/core/browser/translate_ui_delegate_unittest.cc

Also request to merge into M53 since it missed the M53 branching

[Automated comment] DEPS changes referenced in bugdroid comments, needs manual review.

Thanks ftang@ for the confirmation. 

Verified the merge as per C#8 on the latest M-52(52.0.2743.75 /2743@{#617}) on Windows-7 and Linux Ubuntu 14.04. This is working as intended and 'Always translate' never gets checked by default.

Approving merge to M53 branch 2785 based on comment #19. Please merge ASAP. Thank you.

Please merge your change to M53 branch 2785 ASAP (latest by 4:00 PM PST on Monday, 07/18) in order to make it to M53 dev release next week before Beta promotion.

groby - could you merge this to M53 for me?

As far as I can tell, this made it into M53. Nothing to merge. 

yeah, no merge is needed. 
CL listed at comment #4 (https://codereview.chromium.org/2090283002) Cr-Commit-Position: refs/heads/master@{#403232}. M53 Branched Chromium at revision: 403382. Removing "Merge-Approved-53" label. 
 

Frank: Is this fixed, then?