Build property trees for the HUD layer when using layer lists

Build property trees for the HUD layer when using layer lists

When using layer lists in the compositor (aka, SPV2 mode), the hud
layer created in the layer tree host will not have property tree
nodes set. This patch ensures these nodes are set by the layer tree
host.

With this patch, running with the following flags does not crash:
--enable-slimming-paint-v2 --show-paint-rects

BUG=698066
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

[pdr., 2017-03-23 00:11:59]

Description was changed from

==========
Build property trees for the HUD layer when using layer lists

When using layer lists in the compositor (aka, SPV2 mode), the hud
layer created in the layer tree host will not have property tree
nodes set. This patch ensures these nodes are set by the layer tree
host.

With this patch, running with the following flags does not crash:
--enable-slimming-paint-v2 --show-paint-rects

BUG=698066
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Build property trees for the HUD layer when using layer lists

When using layer lists in the compositor (aka, SPV2 mode), the hud
layer created in the layer tree host will not have property tree
nodes set. This patch ensures these nodes are set by the layer tree
host.

With this patch, running with the following flags does not crash:
--enable-slimming-paint-v2 --show-paint-rects

BUG=698066
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[pdr., 2017-03-23 00:12:31]

The CQ bit was checked by pdr@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-23 00:13:37]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-23 02:56:24]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-03-23 02:56:26]

Dry run: This issue passed the CQ dry run.