Revert of [tools/perf] Keep both browsers open from the start of dual browser test

Revert of [tools/perf] Keep both browsers open from the start of dual browser test (patchset #1 id:1 of https://codereview.chromium.org/2073713003/ )

Reason for revert:
Broke WPR on the benchmark

Original issue's description:
> [tools/perf] Keep both browsers open from the start of dual browser test
>
> At the start of the story set, open the browsers associated with all
> stories. This makes sure that, when taking memory dumps, we always get
> a dump for all browsers all the time.
>
> BUG=616043
>
> Committed: https://crrev.com/f41edc4cf5d1b086ad00d70bf9fcb51d3fe9183e
> Cr-Commit-Position: refs/heads/master@{#400667}

TBR=nednguyen@google.com,primiano@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=616043
Committed: https://crrev.com/a0abfdfa0a7131d8dc12f7baf3cc4d76e4e5ea71
Cr-Commit-Position: refs/heads/master@{#401264}

[perezju, 2016-06-22 12:00:23]

The CQ bit was checked by perezju@chromium.org

[perezju, 2016-06-22 12:00:23]

Created Revert of [tools/perf] Keep both browsers open from the start of dual
browser test

[commit-bot: I haz the power, 2016-06-22 12:00:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2084393002/1

[commit-bot: I haz the power, 2016-06-22 12:59:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-22 13:02:09]

Description was changed from

==========
Revert of [tools/perf] Keep both browsers open from the start of dual browser
test (patchset #1 id:1 of https://codereview.chromium.org/2073713003/ )

Reason for revert:
Broke WPR on the benchmark

Original issue's description:
> [tools/perf] Keep both browsers open from the start of dual browser test
> 
> At the start of the story set, open the browsers associated with all
> stories. This makes sure that, when taking memory dumps, we always get
> a dump for all browsers all the time.
> 
> BUG=616043
> 
> Committed: https://crrev.com/f41edc4cf5d1b086ad00d70bf9fcb51d3fe9183e
> Cr-Commit-Position: refs/heads/master@{#400667}

TBR=nednguyen@google.com,primiano@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=616043
==========

to

==========
Revert of [tools/perf] Keep both browsers open from the start of dual browser
test (patchset #1 id:1 of https://codereview.chromium.org/2073713003/ )

Reason for revert:
Broke WPR on the benchmark

Original issue's description:
> [tools/perf] Keep both browsers open from the start of dual browser test
>
> At the start of the story set, open the browsers associated with all
> stories. This makes sure that, when taking memory dumps, we always get
> a dump for all browsers all the time.
>
> BUG=616043
>
> Committed: https://crrev.com/f41edc4cf5d1b086ad00d70bf9fcb51d3fe9183e
> Cr-Commit-Position: refs/heads/master@{#400667}

TBR=nednguyen@google.com,primiano@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=616043

Committed: https://crrev.com/a0abfdfa0a7131d8dc12f7baf3cc4d76e4e5ea71
Cr-Commit-Position: refs/heads/master@{#401264}
==========

[commit-bot: I haz the power, 2016-06-22 13:02:10]

Patchset 1 (id:??) landed as
https://crrev.com/a0abfdfa0a7131d8dc12f7baf3cc4d76e4e5ea71
Cr-Commit-Position: refs/heads/master@{#401264}