Don't use system libpng by default. It causes security maintenance problems

Don't use system libpng by default. It causes security maintenance problems
for ChromeOS. It's worth noting that we also don't use the system library
for many other important components such as libxml.

BUG=112822
R=wad,abarth
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=121199

[Chris Evans, 2012-02-08 03:28:29]

Will, in terms of impact, I think ChromeOS should "own" this CL.

[Will Drewry, 2012-02-08 03:31:00]

LGTM

I think the binary size to maintainability tradeoff makes sense -- especially in
the short-term.  I think in the longer term we'll want to test to see if the
binary size is worse (net) than the linker fix up time penalties at boot.

[commit-bot: I haz the power, 2012-02-08 05:19:31]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer or
a lowly provisional committer, _not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[Tom Sepez, 2012-02-08 05:26:04]

Rubberstamp LGTM.

[commit-bot: I haz the power, 2012-02-08 05:32:23]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer or
a lowly provisional committer, _not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[commit-bot: I haz the power, 2012-02-08 05:43:14]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer or
a lowly provisional committer, _not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[abarth-chromium, 2012-02-08 05:49:36]

I attempt to LGTM it

[commit-bot: I haz the power, 2012-02-08 05:50:31]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/cevans@chromium.org/9365007/2001

[commit-bot: I haz the power, 2012-02-08 06:56:59]

The commit queue went berserk retrying too often for a
seemingly flaky test. Builder is linux_rel, revision is 120943, job name
was 9365007-2001 (previous was lost) (previous was lost) (previous was lost)
(previous was lost).

[commit-bot: I haz the power, 2012-02-08 19:39:21]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/cevans@chromium.org/9365007/2001

[commit-bot: I haz the power, 2012-02-08 21:43:53]

Change committed as 121044