cc : Workaround for null layer impls and invalid property tree indices

cc : Workaround for null layer impls and invalid property tree indices

Temporary Workarounds to prevent crashing when we a null layer_impl in
draw_property_utils::FindLayersThatNeedUpdates and invalid property
tree indices in draw_property_utils::LayerShouldBeSkippedInternal

BUG=725851, 726423
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2901393004
Cr-Original-Commit-Position: refs/heads/master@{#475178}
Review-Url: https://codereview.chromium.org/2915653002 .
Cr-Commit-Position: refs/branch-heads/3071@{#725}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/d86317b087ace8959d3f68936fb346a87a9b0ea3

[Khushal, 2017-05-30 21:07:39]

Description was changed from

==========
cc : Workaround for null layer impls and invalid property tree indices

Temporary Workarounds to prevent crashing when we a null layer_impl in
draw_property_utils::FindLayersThatNeedUpdates and invalid property
tree indices in draw_property_utils::LayerShouldBeSkippedInternal

BUG=725851,726423
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2901393004
Cr-Commit-Position: refs/heads/master@{#475178}
(cherry picked from commit 954e46372100531c3e780f6c64da5fd91e988f4b)
==========

to

==========
cc : Workaround for null layer impls and invalid property tree indices

Temporary Workarounds to prevent crashing when we a null layer_impl in
draw_property_utils::FindLayersThatNeedUpdates and invalid property
tree indices in draw_property_utils::LayerShouldBeSkippedInternal

BUG=725851,726423
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2901393004
Cr-Original-Commit-Position: refs/heads/master@{#475178}
Review-Url: https://codereview.chromium.org/2915653002 .
Cr-Commit-Position: refs/branch-heads/3071@{#725}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/d86317b087ace8959d3f68936fb3...
==========

[Khushal, 2017-05-30 21:07:41]

Committed patchset #1 (id:1) manually as
d86317b087ace8959d3f68936fb346a87a9b0ea3.