linux_aura: Improve window drag performance.

linux_aura: Improve window drag performance.

By delaying actually moving the window, we stop flooding the message
loop. This helps, but doesn't perfectly solve, the performance problems
with message dragging.

This patch adds a lot of TRACE_EVENT calls which were used to narrow
down exactly what was going on.

BUG=313903
R=ben@chromium.org, piman@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=233035

[Elliot Glaysher, 2013-11-04 20:32:42]

piman: x11 review
ben: owners stamp for all the files I added trace event calls to.

[Ben Goodger (Google), 2013-11-04 20:39:16]

trace events lgtm

[piman, 2013-11-04 20:46:30]

lgtm

[commit-bot: I haz the power, 2013-11-05 00:24:43]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/erg@chromium.org/56053005/230001

[commit-bot: I haz the power, 2013-11-05 03:19:21]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/erg@chromium.org/56053005/230001

[commit-bot: I haz the power, 2013-11-05 06:48:34]

Retried try job too often on win_rel for step(s) content_unittests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[Elliot Glaysher, 2013-11-05 18:33:53]

Committed patchset #2 manually as r233035 (presubmit successful).