Run draw callback immediately if no Display is damaged.

Run draw callback immediately if no Display is damaged.

This may cause the draw callback to be run earlier than before if the Surface would later be added to a Display, but prevents it ensures that the callback runs if the Surface wouldn't be drawn at all

BUG=440269
Committed: https://crrev.com/c247da12fcca15fdcc948024287b94d6e63e9784
Cr-Commit-Position: refs/heads/master@{#313212}

[jbauman, 2015-01-12 20:32:18]

jbauman@chromium.org changed reviewers:
+ jamesr@chromium.org

[jbauman, 2015-01-16 00:58:14]

ping. This seems like one way to handle Surfaces that aren't aggregated in
Displays. I thought about giving each surface a primary Display, and do
callback.Run(false) if the Display draws but the Surface isn't aggregated in it,
but that doesn't handle the case where the Display doesn't draw because nothing
in it changes. If you want I could have it delay the draw callback instead (for
16ms or 32ms or whatever), to ensure that a non-visible spinning child window
doesn't spin way too fast.

[jamesr, 2015-01-23 06:23:06]

Yeah, this case is really tough.  I think this could make scheduling hard when a
new surface is first coming into existence since it could submit a frame that
tries to get aggregated before its containing frame is submitted, leading to an
instant "ack" even though it should really wait, but I think the only way around
this is to use a centralized scheduler and not try to sit on ACKs everywhere.

lgtm but consider using an enum instead of bool for 'drawn'.  It's slightly
clearer and easier to extend if we want to communicate more data on this path in
the future.

[jbauman, 2015-01-27 02:03:02]

The CQ bit was checked by jbauman@chromium.org

[commit-bot: I haz the power, 2015-01-27 02:03:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/792383004/100001

[commit-bot: I haz the power, 2015-01-27 02:53:26]

Committed patchset #6 (id:100001)

[commit-bot: I haz the power, 2015-01-27 02:54:12]

Patchset 6 (id:??) landed as
https://crrev.com/c247da12fcca15fdcc948024287b94d6e63e9784
Cr-Commit-Position: refs/heads/master@{#313212}