cc: Add raster_enabled setting

cc: Add raster_enabled setting

In order to support impl-side painting plus an embedder without a
message loop, cc needs a setting to disable raster.  Rastering with
impl-side painting requires a task runner (and DCHECKs this).  This
setting notifies cc that there's no need for a tile manager.

Thankfully, tile manager is already considered optional in almost all
contexts, and so just a few more callsites needed to be cleaned up to
fix a few crashes.

With this patch, all cc unittests pass with impl-side painting on by
default.

Committed: https://crrev.com/bdb6fd2037025923c986d1e3552cf9f99a634554
Cr-Commit-Position: refs/heads/master@{#319840}

[enne (OOO), 2015-03-06 22:04:20]

enne@chromium.org changed reviewers:
+ danakj@chromium.org

[enne (OOO), 2015-03-06 22:07:00]

https://codereview.chromium.org/984113004/diff/1/cc/trees/layer_tree_host_uni...
File cc/trees/layer_tree_host_unittest_no_message_loop.cc (right):

https://codereview.chromium.org/984113004/diff/1/cc/trees/layer_tree_host_uni...
cc/trees/layer_tree_host_unittest_no_message_loop.cc:107:
settings.raster_enabled = false;
This test does a full composite pass.  I could add some LTH tests or a
non-raster pixel test too if you think test coverage is missing.

[enne (OOO), 2015-03-10 00:28:06]

enne@chromium.org changed reviewers:
+ reveman@chromium.org

[enne (OOO), 2015-03-10 00:28:10]

+reveman

[reveman, 2015-03-10 04:01:51]

https://codereview.chromium.org/984113004/diff/1/cc/trees/layer_tree_settings.cc
File cc/trees/layer_tree_settings.cc (right):

https://codereview.chromium.org/984113004/diff/1/cc/trees/layer_tree_settings...
cc/trees/layer_tree_settings.cc:18: raster_enabled(true),
how is raster done when this is false, on demand? would tile_management_enabled
more accurately describe this setting?

[enne (OOO), 2015-03-10 04:05:24]

https://codereview.chromium.org/984113004/diff/1/cc/trees/layer_tree_settings.cc
File cc/trees/layer_tree_settings.cc (right):

https://codereview.chromium.org/984113004/diff/1/cc/trees/layer_tree_settings...
cc/trees/layer_tree_settings.cc:18: raster_enabled(true),
On 2015/03/10 04:01:51, reveman wrote:
> how is raster done when this is false, on demand? would
tile_management_enabled
> more accurately describe this setting? 

It's not done at all.

[reveman, 2015-03-10 04:06:52]

lgtm

https://codereview.chromium.org/984113004/diff/1/cc/trees/layer_tree_settings.cc
File cc/trees/layer_tree_settings.cc (right):

https://codereview.chromium.org/984113004/diff/1/cc/trees/layer_tree_settings...
cc/trees/layer_tree_settings.cc:18: raster_enabled(true),
On 2015/03/10 04:05:24, enne wrote:
> On 2015/03/10 04:01:51, reveman wrote:
> > how is raster done when this is false, on demand? would
> tile_management_enabled
> > more accurately describe this setting? 
> 
> It's not done at all.

Acknowledged.

[enne (OOO), 2015-03-10 04:17:47]

The CQ bit was checked by enne@chromium.org

[commit-bot: I haz the power, 2015-03-10 04:17:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/984113004/1

[commit-bot: I haz the power, 2015-03-10 06:02:09]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-10 06:02:41]

Patchset 1 (id:??) landed as
https://crrev.com/bdb6fd2037025923c986d1e3552cf9f99a634554
Cr-Commit-Position: refs/heads/master@{#319840}

[danakj, 2015-03-10 16:54:46]

lgtm 2