Prepare for -Wall for third-party code, -Wextra for chromium_code

Prepare for -Wall for third-party code, -Wextra for chromium_code

This lands patch set 16 of https://codereview.chromium.org/1551753002/
(reviewed there), except for the changes to build/common.gypi and
build/config/compiler/BUILD.gn.  The changes to these two files are likely
to break some bot I don't know about, and I don't want to keep reverting
and relanding all these files.  So this lands the parts that are hopefully
harmless separately.

BUG=573250
TBR=thestig

Committed: https://crrev.com/29de2c811de5e5fa6eb238bbcd45796907c037bd
Cr-Commit-Position: refs/heads/master@{#367252}

[Nico, 2015-12-31 15:34:49]

Description was changed from

==========
Prepare for -Wall for third-party code, -Wextra for chromium_code

This lands patch set 16 of https://codereview.chromium.org/1551753002/
(reviewed there), except for the changes to build/common.gypi and
build/config/compiler/BUILD.gn.  The changes to these two files are likely
to break some bot I don't know about, and I don't want to keep reverting
and relanding all these files.  So this lands the parts that are hopefully
harmless separately.

BUG=573250
==========

to

==========
Prepare for -Wall for third-party code, -Wextra for chromium_code

This lands patch set 16 of https://codereview.chromium.org/1551753002/
(reviewed there), except for the changes to build/common.gypi and
build/config/compiler/BUILD.gn.  The changes to these two files are likely
to break some bot I don't know about, and I don't want to keep reverting
and relanding all these files.  So this lands the parts that are hopefully
harmless separately.

BUG=573250
TBR=thestig
==========

[Nico, 2015-12-31 15:35:00]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2015-12-31 15:35:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1557733002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1557733002/1

[commit-bot: I haz the power, 2015-12-31 17:26:14]

Description was changed from

==========
Prepare for -Wall for third-party code, -Wextra for chromium_code

This lands patch set 16 of https://codereview.chromium.org/1551753002/
(reviewed there), except for the changes to build/common.gypi and
build/config/compiler/BUILD.gn.  The changes to these two files are likely
to break some bot I don't know about, and I don't want to keep reverting
and relanding all these files.  So this lands the parts that are hopefully
harmless separately.

BUG=573250
TBR=thestig
==========

to

==========
Prepare for -Wall for third-party code, -Wextra for chromium_code

This lands patch set 16 of https://codereview.chromium.org/1551753002/
(reviewed there), except for the changes to build/common.gypi and
build/config/compiler/BUILD.gn.  The changes to these two files are likely
to break some bot I don't know about, and I don't want to keep reverting
and relanding all these files.  So this lands the parts that are hopefully
harmless separately.

BUG=573250
TBR=thestig
==========

[commit-bot: I haz the power, 2015-12-31 17:26:15]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-31 17:27:19]

Description was changed from

==========
Prepare for -Wall for third-party code, -Wextra for chromium_code

This lands patch set 16 of https://codereview.chromium.org/1551753002/
(reviewed there), except for the changes to build/common.gypi and
build/config/compiler/BUILD.gn.  The changes to these two files are likely
to break some bot I don't know about, and I don't want to keep reverting
and relanding all these files.  So this lands the parts that are hopefully
harmless separately.

BUG=573250
TBR=thestig
==========

to

==========
Prepare for -Wall for third-party code, -Wextra for chromium_code

This lands patch set 16 of https://codereview.chromium.org/1551753002/
(reviewed there), except for the changes to build/common.gypi and
build/config/compiler/BUILD.gn.  The changes to these two files are likely
to break some bot I don't know about, and I don't want to keep reverting
and relanding all these files.  So this lands the parts that are hopefully
harmless separately.

BUG=573250
TBR=thestig

Committed: https://crrev.com/29de2c811de5e5fa6eb238bbcd45796907c037bd
Cr-Commit-Position: refs/heads/master@{#367252}
==========

[commit-bot: I haz the power, 2015-12-31 17:27:20]

Patchset 1 (id:??) landed as
https://crrev.com/29de2c811de5e5fa6eb238bbcd45796907c037bd
Cr-Commit-Position: refs/heads/master@{#367252}

[Nico, 2015-12-31 22:30:39]

thakis@chromium.org changed reviewers:
+ thestig@chromium.org

[Lei Zhang, 2015-12-31 23:03:17]

lgtm