gpu: Add traces to Produce/Consume texture.

gpu: Add traces to Produce/Consume texture.

Currently consume is expensive. Also, we currently
have no other way of detecting compositor frames
being produced/consumed in the GPU process.

BUG=220561
NOTRY=true

No try since the aura failure isn't related.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=189962

[epenner, 2013-03-20 02:44:30]

Ptal.

[greggman, 2013-03-20 04:58:58]

lgtm

[no sievers, 2013-03-20 18:20:10]

It would be super awesome if you could add two arguments to the trace events
being reported:

- the description of the context doing this (see GetLogPrefix())
- some short hash of the mailboxname (crc-8?)

[epenner, 2013-03-20 19:39:35]

The first was easy. The second I just used the first byte as that seems random
enough for debugging. Indeed it's easy to identify both the double buffering and
the different compositors.

[commit-bot: I haz the power, 2013-03-20 19:54:14]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/epenner@chromium.org/12888005/5002

[commit-bot: I haz the power, 2013-03-21 03:22:51]

Retried try job too often on win7_aura for step(s) browser_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win7_aura&...

[commit-bot: I haz the power, 2013-03-23 00:08:16]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/epenner@chromium.org/12888005/5002

[commit-bot: I haz the power, 2013-03-23 00:58:04]

Change committed as 189962