Only set a valid surface from html_viewer

Only set a valid surface from html_viewer

We have users of html_viewer that do not use the mojo provided services, including the surface service. This change: https://codereview.chromium.org/869343004/ broke them

I think it's right to check this here. Another option would be to do it in layer_tree_host.cc

BUG=

Committed: https://crrev.com/0b46750604491453c46480ab985fec398f97c86e
Cr-Commit-Position: refs/heads/master@{#315157}

[DaveMoore, 2015-02-07 00:16:37]

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

[jamesr, 2015-02-07 00:39:14]

If this embedder of html_viewer doesn't wanna render then we could cut out a lot
of stuff.  Is there any way we could have the embedder tell us what they want so
we can only initialize the parts of blink that are relevant?  In chromium
there's a headless mode for the blink embedding that skips a lot of stuff,
including this.

[jamesr, 2015-02-07 00:50:24]

I think this'll work short term, but look at
content::RenderWidget::never_visible_.  That's something closer to what we want
I think.

lgtm if you want to land this as a stopgap

[DaveMoore, 2015-02-07 00:52:29]

On 2015/02/07 00:39:14, jamesr wrote:
> If this embedder of html_viewer doesn't wanna render then we could cut out a
lot
> of stuff.  Is there any way we could have the embedder tell us what they want
so
> we can only initialize the parts of blink that are relevant?  In chromium
> there's a headless mode for the blink embedding that skips a lot of stuff,
> including this.

We absolutely could do this. We could pass an arg to the html_viewer indicating
it's headless. If this cl is valid though, could you lgtm it? And then we can
add this headless mode.

[DaveMoore, 2015-02-07 01:35:09]

The CQ bit was checked by davemoore@chromium.org

[commit-bot: I haz the power, 2015-02-07 01:35:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/902293002/1

[commit-bot: I haz the power, 2015-02-07 01:58:17]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-07 01:58:48]

Patchset 1 (id:??) landed as
https://crrev.com/0b46750604491453c46480ab985fec398f97c86e
Cr-Commit-Position: refs/heads/master@{#315157}