Reland #2 "ipc: Add a new field num_brokered_attachments to the message header."

Reland #2 "ipc: Add a new field num_brokered_attachments to the message header."

This original version of this CL is causing an unusual crash in Canary. This CL
adds a message verifier to the ipc code so that it can dynamically verify the
contents of this message that is being corrupted. This CL also verifies the
message at several different points in the dispatch process. This will help
narrow down the range of code that is corrupting the message.

I expect this CL to cause ~100 crashes in the next Chrome Canary. I intend to
revert this CL after a single Canary release.

BUG=527588
Committed: https://crrev.com/a2e71be46dc4bdcbb544db479680f65a390ae8f3
Cr-Commit-Position: refs/heads/master@{#349056}

[erikchen, 2015-09-10 00:09:30]

erikchen@chromium.org changed reviewers:
+ avi@chromium.org, tsepez@chromium.org

[erikchen, 2015-09-10 00:09:30]

avi: Looking for a content/ review.
tsepez: Looking for an ipc/ review.

[Avi (use Gerrit), 2015-09-10 00:33:08]

lgtm

good luck

[erikchen, 2015-09-10 01:07:44]

The CQ bit was checked by erikchen@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-09-10 01:08:27]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1334593002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1334593002/40001

[commit-bot: I haz the power, 2015-09-10 02:50:36]

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

[commit-bot: I haz the power, 2015-09-10 02:50:36]

Dry run: This issue passed the CQ dry run.

[Tom Sepez, 2015-09-14 17:33:09]

lgtm

[erikchen, 2015-09-14 17:34:28]

The CQ bit was checked by erikchen@chromium.org

[commit-bot: I haz the power, 2015-09-14 17:35:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1334593002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1334593002/40001

[commit-bot: I haz the power, 2015-09-14 17:40:00]

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

[commit-bot: I haz the power, 2015-09-14 17:40:00]

Try jobs failed on following builders:
  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_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[erikchen, 2015-09-14 17:47:57]

The CQ bit was checked by erikchen@chromium.org

[erikchen, 2015-09-14 17:47:57]

The patchset sent to the CQ was uploaded after l-g-t-m from tsepez@chromium.org,
avi@chromium.org
Link to the patchset: https://codereview.chromium.org/1334593002/#ps60001
(title: "Rebase errors.")

[commit-bot: I haz the power, 2015-09-14 17:48:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1334593002/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1334593002/60001

[commit-bot: I haz the power, 2015-09-14 18:21:07]

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

[commit-bot: I haz the power, 2015-09-14 18:21:08]

Try jobs failed on following builders:
  win8_chromium_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_ng/...)

[erikchen, 2015-09-14 23:32:34]

The CQ bit was checked by erikchen@chromium.org

[commit-bot: I haz the power, 2015-09-14 23:33:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1334593002/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1334593002/60001

[commit-bot: I haz the power, 2015-09-15 00:09:13]

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

[commit-bot: I haz the power, 2015-09-15 00:09:14]

Try jobs failed on following builders:
  win8_chromium_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_ng/...)

[erikchen, 2015-09-15 19:14:05]

The CQ bit was checked by erikchen@chromium.org

[commit-bot: I haz the power, 2015-09-15 19:15:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1334593002/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1334593002/60001

[commit-bot: I haz the power, 2015-09-15 19:50:51]

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

[commit-bot: I haz the power, 2015-09-15 19:50:52]

Try jobs failed on following builders:
  win_chromium_compile_dbg_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_comp...)

[erikchen, 2015-09-15 22:55:20]

The CQ bit was checked by erikchen@chromium.org

[erikchen, 2015-09-15 22:55:20]

The patchset sent to the CQ was uploaded after l-g-t-m from tsepez@chromium.org,
avi@chromium.org
Link to the patchset: https://codereview.chromium.org/1334593002/#ps80001
(title: "Rebase and type error.")

[commit-bot: I haz the power, 2015-09-15 22:55:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1334593002/80001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1334593002/80001

[commit-bot: I haz the power, 2015-09-16 00:59:46]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2015-09-16 01:00:39]

Patchset 5 (id:??) landed as
https://crrev.com/a2e71be46dc4bdcbb544db479680f65a390ae8f3
Cr-Commit-Position: refs/heads/master@{#349056}

[erikchen, 2015-09-16 17:33:44]

A revert of this CL (patchset #5 id:80001) has been created in
https://codereview.chromium.org/1350823002/ by erikchen@chromium.org.

The reason for reverting is: CL was only ever intended to be in 1 canary
release..

[commit-bot: I haz the power, 2015-09-23 12:52:05]

Patchset 5 (id:??) landed as
https://crrev.com/a2e71be46dc4bdcbb544db479680f65a390ae8f3
Cr-Commit-Position: refs/heads/master@{#349056}