Revert of Revert of IPC::ChannelMojo: Make IPC handling robust against bad messages.

Revert of Revert of IPC::ChannelMojo: Make IPC handling robust against bad messages. (patchset #1 id:1 of https://codereview.chromium.org/883373002/)

Reason for revert:
Wrong revert, ipc fuzzer broke because of something else.

Original issue's description:
> Revert of IPC::ChannelMojo: Make IPC handling robust against bad messages. (patchset #3 id:40001 of https://codereview.chromium.org/725733002/)
>
> Reason for revert:
> Broke ipc fuzzer
>
> Original issue's description:
> > IPC::ChannelMojo: Make IPC handling robust against bad messages.
> >
> > This change replaces some DCHECK()s with real error handling.
> > They happen when it receives broken messages.
> >
> > BUG=428800
> > R=viettrungluu@chromium.org
> >
> > Committed: https://crrev.com/185ffdf58f85e47db9666d2ad9b80ff9bd7fa54b
> > Cr-Commit-Position: refs/heads/master@{#304102}
>
> TBR=viettrungluu@chromium.org,morrita@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=428800
>
> Committed: https://crrev.com/726621f93d2802dfc2c90732c7133145c9854e38
> Cr-Commit-Position: refs/heads/master@{#313778}

TBR=viettrungluu@chromium.org,morrita@chromium.org,tsepez@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=428800
Committed: https://crrev.com/1f289ac93a7e90ca9445f97ea58f5e3961bd9539
Cr-Commit-Position: refs/heads/master@{#313780}

[inferno, 2015-01-29 20:43:52]

Created Revert of Revert of IPC::ChannelMojo: Make IPC handling robust against
bad messages.

[inferno, 2015-01-29 20:44:26]

The CQ bit was unchecked by inferno@chromium.org

[inferno, 2015-01-29 20:46:06]

The CQ bit was checked by inferno@chromium.org

[commit-bot: I haz the power, 2015-01-29 20:47:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/892503002/1

[commit-bot: I haz the power, 2015-01-29 20:48:22]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-29 20:50:45]

Patchset 1 (id:??) landed as
https://crrev.com/1f289ac93a7e90ca9445f97ea58f5e3961bd9539
Cr-Commit-Position: refs/heads/master@{#313780}