Revert of Have each SandboxedProcessLauncherDelegate maintain a zygote.

Revert of Have each SandboxedProcessLauncherDelegate maintain a zygote. (patchset #16 id:500001 of https://codereview.chromium.org/1532423003/ )

Reason for revert:
This change has caused several performance concerns, and those needs to be addressed before we ship this. Because my focus is shifting to other goals for the time being, I am reverting this until it can be sped up and re-landed. 

Original issue's description:
> Have each SandboxedProcessLauncherDelegate maintain a zygote.
> 
> To improve component updates of PPAPI plugins, Chrome needs multiple zygotes.
> This will allow the PPAPI zygote to be recreated when a plugin is updated.
> This CL allows Chrome to maintain a zygote for each process type by having
> each SandboxedProcessLauncherDelegate maintain a class which can communicate
> with its respective zygote. This CL will be followed up with work to allow
> customization of zygotes, which will give Chrome the improve component update
> experience.
> 
> BUG=569191
> 
> Committed: https://crrev.com/3c1e16b490255119b6f70f94d1716645e897b185
> Cr-Commit-Position: refs/heads/master@{#370488}
> 
> Committed: https://crrev.com/afd49a83be5da2df6667a2afd14239d7783aff52
> Cr-Commit-Position: refs/heads/master@{#371042}

TBR=mdempsky@chromium.org,thestig@chromium.org,avi@chromium.org,mseaborn@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=569191

[Greg K, 2016-01-28 19:19:02]

Created Revert of Have each SandboxedProcessLauncherDelegate maintain a zygote.

[mdempsky, 2016-01-28 19:20:52]

lgtm

[commit-bot: I haz the power, 2016-01-28 19:21:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1640123005/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1640123005/1

[commit-bot: I haz the power, 2016-01-28 19:24:20]

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

[commit-bot: I haz the power, 2016-01-28 19:24:21]

Try jobs failed on following builders:
  linux_chromium_compile_dbg_32_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  ios_dbg_simulator_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_dbg_simulator...)
  ios_rel_device_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)
  mac_chromium_compile_dbg_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)
  mac_chromium_gn_rel on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_gn_r...)
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Greg K, 2016-06-01 22:06:42]

Description was changed from

==========
Revert of Have each SandboxedProcessLauncherDelegate maintain a zygote.
(patchset #16 id:500001 of https://codereview.chromium.org/1532423003/ )

Reason for revert:
This change has caused several performance concerns, and those needs to be
addressed before we ship this. Because my focus is shifting to other goals for
the time being, I am reverting this until it can be sped up and re-landed. 

Original issue's description:
> Have each SandboxedProcessLauncherDelegate maintain a zygote.
> 
> To improve component updates of PPAPI plugins, Chrome needs multiple zygotes.
> This will allow the PPAPI zygote to be recreated when a plugin is updated.
> This CL allows Chrome to maintain a zygote for each process type by having
> each SandboxedProcessLauncherDelegate maintain a class which can communicate
> with its respective zygote. This CL will be followed up with work to allow
> customization of zygotes, which will give Chrome the improve component update
> experience.
> 
> BUG=569191
> 
> Committed: https://crrev.com/3c1e16b490255119b6f70f94d1716645e897b185
> Cr-Commit-Position: refs/heads/master@{#370488}
> 
> Committed: https://crrev.com/afd49a83be5da2df6667a2afd14239d7783aff52
> Cr-Commit-Position: refs/heads/master@{#371042}

TBR=mdempsky@chromium.org,thestig@chromium.org,avi@chromium.org,mseaborn@chro...
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=569191
==========

to

==========
Revert of Have each SandboxedProcessLauncherDelegate maintain a zygote.
(patchset #16 id:500001 of https://codereview.chromium.org/1532423003/ )

Reason for revert:
This change has caused several performance concerns, and those needs to be
addressed before we ship this. Because my focus is shifting to other goals for
the time being, I am reverting this until it can be sped up and re-landed. 

Original issue's description:
> Have each SandboxedProcessLauncherDelegate maintain a zygote.
> 
> To improve component updates of PPAPI plugins, Chrome needs multiple zygotes.
> This will allow the PPAPI zygote to be recreated when a plugin is updated.
> This CL allows Chrome to maintain a zygote for each process type by having
> each SandboxedProcessLauncherDelegate maintain a class which can communicate
> with its respective zygote. This CL will be followed up with work to allow
> customization of zygotes, which will give Chrome the improve component update
> experience.
> 
> BUG=569191
> 
> Committed: https://crrev.com/3c1e16b490255119b6f70f94d1716645e897b185
> Cr-Commit-Position: refs/heads/master@{#370488}
> 
> Committed: https://crrev.com/afd49a83be5da2df6667a2afd14239d7783aff52
> Cr-Commit-Position: refs/heads/master@{#371042}

TBR=mdempsky@chromium.org,thestig@chromium.org,avi@chromium.org,mseaborn@chro...
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=569191
==========