Use an X event loop in the GPU process on Linux.

Use an X event loop in the GPU process on Linux.

In future patches, X windows will be created in the GPU
process, and events sent to these windows will need to
be forwarded to their parent windows.

Linux uses GTK as the default UI event loop type, but
GTK is not in the GPU process, so the X11 event loop
type is used instead.

Update package dependencies.

This will cause a regression in nacl_helper-text/text. Test
expectations will need to be updated.

BUG=145600
TBR=thakis, piman, mmoss, erg

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=222894

[ccameron, 2013-09-12 18:44:58]

This caused the following perf regression for nacl_helper:
http://build.chromium.org/p/chromium/builders/Linux%20x64/builds/55508

We'll be using X more directly (as compared with using GTK) in the next few
releases, and we'll be getting rid of GTK once we're done switching to aura.
It looks like this regression is a consequence of touching more X libraries,
so it is expected.

Please LMK if you disagree.

[ccameron, 2013-09-12 19:10:11]

Adding ncbray, since he's the nacl-sheriff.

[Nick Bray (chromium), 2013-09-12 19:55:52]

The size regression for NaCl helper 1) appears to be unavoidable and 2) not that
large, so I see no issues from the NaCl point of view.

I will note on the commit message, however, "adjusting perf expectations" !=
"adding a suppression".  Also, if you were reverted for a minor size regression
(committing is the only way I know these things are caught?) I believe the perf
sheriffing guide says not to revert in these cases, FYI.

[ccameron, 2013-09-12 19:59:28]

Thanks!!

[commit-bot: I haz the power, 2013-09-12 19:59:41]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ccameron@chromium.org/23530050/1

[commit-bot: I haz the power, 2013-09-12 22:51:12]

Change committed as 222894