Revert of Enable BrowserScheduler.RedirectHistoryService experiment on trunk.

Revert of Enable BrowserScheduler.RedirectHistoryService experiment on trunk. (patchset #6 id:120001 of https://codereview.chromium.org/2592813002/ )

Reason for revert:
Suspecting this CL of causing test failures:
  ProfileBrowserTest.CreateNewProfileSynchronous
  ProfileBrowserTest.OffTheRecordURLRequestContextIsolation
  ProfileBrowserTest.CreateOldProfileSynchronous
  ProfileBrowserTest.ExitType

b/c error messages mention HistoryBackend

https://uberchromegw.corp.google.com/i/chromium.memory/builders/Mac%20ASan%2064%20Tests%20%281%29/builds/25845

Original issue's description:
> Enable BrowserScheduler.RedirectHistoryService experiment on trunk.
> 
> Add .WithSyncPrimitives() trait to history service's backend
> TaskRunner. Required by ChromeHistoryBackendClient::IsBookmarked().
> 
> BUG=661143
> TBR=sky@chromium.org (history_service.cc tweak to experiment)
> 
> Committed: https://crrev.com/4aa30591e0953da7e0c54ffdb91856e496d16b5f
> Cr-Commit-Position: refs/heads/master@{#440418}

TBR=rkaplow@chromium.org,sky@chromium.org,gab@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=661143

[hcarmona, 2016-12-22 19:43:57]

The CQ bit was checked by hcarmona@chromium.org

[hcarmona, 2016-12-22 19:43:58]

Created Revert of Enable BrowserScheduler.RedirectHistoryService experiment on
trunk.

[commit-bot: I haz the power, 2016-12-22 19:44:12]

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, 2016-12-22 19:44:42]

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

[commit-bot: I haz the power, 2016-12-22 19:44:43]

Failed to apply patch for testing/variations/fieldtrial_testing_config.json:
While running git apply --index -p1;
  error: patch failed: testing/variations/fieldtrial_testing_config.json:212
  error: testing/variations/fieldtrial_testing_config.json: patch does not apply

Patch:       testing/variations/fieldtrial_testing_config.json
Index: testing/variations/fieldtrial_testing_config.json
diff --git a/testing/variations/fieldtrial_testing_config.json
b/testing/variations/fieldtrial_testing_config.json
index
bb6a3247d1e02b4a31f83c42901571999e76ff78..dd6bbd7a76c882be733967e0c8fe78ba25b3062f
100644
--- a/testing/variations/fieldtrial_testing_config.json
+++ b/testing/variations/fieldtrial_testing_config.json
@@ -212,10 +212,7 @@
             ],
             "experiments": [
                 {
-                    "name": "Default",
-                    "params": {
-                        "RedirectHistoryService": "true"
-                    }
+                    "name": "Default"
                 },
                 {
                     "name": "EnableViaFlag",

[gab, 2016-12-22 19:54:04]

On 2016/12/22 19:44:43, commit-bot: I haz the power wrote:
> Failed to apply patch for testing/variations/fieldtrial_testing_config.json:
> While running git apply --index -p1;
>   error: patch failed: testing/variations/fieldtrial_testing_config.json:212
>   error: testing/variations/fieldtrial_testing_config.json: patch does not
apply
> 
> Patch:       testing/variations/fieldtrial_testing_config.json
> Index: testing/variations/fieldtrial_testing_config.json
> diff --git a/testing/variations/fieldtrial_testing_config.json
> b/testing/variations/fieldtrial_testing_config.json
> index
>
bb6a3247d1e02b4a31f83c42901571999e76ff78..dd6bbd7a76c882be733967e0c8fe78ba25b3062f
> 100644
> --- a/testing/variations/fieldtrial_testing_config.json
> +++ b/testing/variations/fieldtrial_testing_config.json
> @@ -212,10 +212,7 @@
>              ],
>              "experiments": [
>                  {
> -                    "name": "Default",
> -                    "params": {
> -                        "RedirectHistoryService": "true"
> -                    }
> +                    "name": "Default"
>                  },
>                  {
>                      "name": "EnableViaFlag",

Rebased on trunk and landing in https://codereview.chromium.org/2598033003