Revert of Update docs and command line flags for MB.

Revert of Update docs and command line flags for MB. (patchset #3 id:40001 of https://codereview.chromium.org/1206633003/)

Reason for revert:
This CL appears to be causing tryjobs to fail. See:

http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_gn_rel/builds/110208/steps/analyze/logs/stdio

and https://crbug.com/510655

Original issue's description:
> Update docs and command line flags for MB.
>
> This adds the information about how the integration w/ isolates works,
> and does a bunch of additional cleanup to make sure everything is
> documented and in sync.
>
> R=maruel@chromium.org
> BUG=
>
> Committed: https://crrev.com/747cb269970294b7928ca30a3cde192c90072d13
> Cr-Commit-Position: refs/heads/master@{#338951}

TBR=maruel@chromium.org,dpranke@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Committed: https://crrev.com/f061c99013c416af0eeb06a2d898e03a4bdc722e
Cr-Commit-Position: refs/heads/master@{#338967}

[tsergeant, 2015-07-16 01:32:40]

Created Revert of Update docs and command line flags for MB.

[commit-bot: I haz the power, 2015-07-16 01:32:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1234343003/1

[commit-bot: I haz the power, 2015-07-16 01:34:08]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-16 01:35:20]

Patchset 1 (id:??) landed as
https://crrev.com/f061c99013c416af0eeb06a2d898e03a4bdc722e
Cr-Commit-Position: refs/heads/master@{#338967}

[Dirk Pranke, 2015-07-16 03:25:35]

On 2015/07/16 01:35:20, commit-bot: I haz the power wrote:
> Patchset 1 (id:??) landed as
> https://crrev.com/f061c99013c416af0eeb06a2d898e03a4bdc722e
> Cr-Commit-Position: refs/heads/master@{#338967}

lgtm, thanks!