Animated scroll shouldn't require main-frame for OOPIFs.

Animated scroll shouldn't require main-frame for OOPIFs.

At present the animated scroll code for mouse wheels will mark as
SCROLL_ON_IMPL any attempt to scroll if there is no scrollable
layer, and in an OOPIF this causes the GestureScrollUpdate to be
marked as consumed when in fact it isn't. In turn, this prevents
the GestureScrollUpdate from bubbling to the embedder.

This CL fixes LayerTreeHostImpl::ScrollAnimated() to corrently report
such GestureScrollUpdate events as ignored, so they can bubble to the
embedder.

This CL has no behavioral changes for Mac, as it does not support
smooth scrolling.

BUG=701178
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2785533003
Cr-Commit-Position: refs/heads/master@{#465828}
(cherry picked from commit a755e30003e89da8ed1ee6f9e4e039acb395e3af)

Review-Url: https://codereview.chromium.org/2833423003 .
Cr-Commit-Position: refs/branch-heads/3071@{#166}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/bd145783f35871897d7bcf24b194cae2631186b3

[wjmaclean, 2017-04-24 17:06:53]

Description was changed from

==========
Animated scroll shouldn't require main-frame for OOPIFs.

At present the animated scroll code for mouse wheels will mark as
SCROLL_ON_IMPL any attempt to scroll if there is no scrollable
layer, and in an OOPIF this causes the GestureScrollUpdate to be
marked as consumed when in fact it isn't. In turn, this prevents
the GestureScrollUpdate from bubbling to the embedder.

This CL fixes LayerTreeHostImpl::ScrollAnimated() to corrently report
such GestureScrollUpdate events as ignored, so they can bubble to the
embedder.

This CL has no behavioral changes for Mac, as it does not support
smooth scrolling.

BUG=701178
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2785533003
Cr-Commit-Position: refs/heads/master@{#465828}
(cherry picked from commit a755e30003e89da8ed1ee6f9e4e039acb395e3af)
==========

to

==========
Animated scroll shouldn't require main-frame for OOPIFs.

At present the animated scroll code for mouse wheels will mark as
SCROLL_ON_IMPL any attempt to scroll if there is no scrollable
layer, and in an OOPIF this causes the GestureScrollUpdate to be
marked as consumed when in fact it isn't. In turn, this prevents
the GestureScrollUpdate from bubbling to the embedder.

This CL fixes LayerTreeHostImpl::ScrollAnimated() to corrently report
such GestureScrollUpdate events as ignored, so they can bubble to the
embedder.

This CL has no behavioral changes for Mac, as it does not support
smooth scrolling.

BUG=701178
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2785533003
Cr-Commit-Position: refs/heads/master@{#465828}
(cherry picked from commit a755e30003e89da8ed1ee6f9e4e039acb395e3af)

Review-Url: https://codereview.chromium.org/2833423003 .
Cr-Commit-Position: refs/branch-heads/3071@{#166}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/bd145783f35871897d7bcf24b194...
==========

[wjmaclean, 2017-04-24 17:06:54]

Committed patchset #1 (id:1) manually as
bd145783f35871897d7bcf24b194cae2631186b3.