Prevent AutoscrollForSelection when selecting text in a fixed-position element.

Prevent AutoscrollForSelection when selecting text in a fixed-position element.

AutoscrollForSelection is triggered when selecting text and dragging mouse out
of the container. However, we don't want selecting text in a fixed-position
element triggers autoscroll otherwhere. Inside findAutoscrollable, when we find
the object is inside a fixed-position element, we should prevent
AutoscrollForSelection from happening.

BUG=655489
Review-Url: https://codereview.chromium.org/2441683002
Cr-Commit-Position: refs/heads/master@{#427146}
(cherry picked from commit 53546e297f782849d9da8004508d0b85c2fd931c)

Committed: https://chromium.googlesource.com/chromium/src/+/9021d6508dfddb41393ae8fa2af2e6dae8cac676

[majidvp, 2016-10-27 18:31:03]

Description was changed from

==========
Prevent AutoscrollForSelection when selecting text in a fixed-position element.

AutoscrollForSelection is triggered when selecting text and dragging mouse out
of the container. However, we don't want selecting text in a fixed-position
element triggers autoscroll otherwhere. Inside findAutoscrollable, when we find
the object is inside a fixed-position element, we should prevent
AutoscrollForSelection from happening.

BUG=655489

Review-Url: https://codereview.chromium.org/2441683002
Cr-Commit-Position: refs/heads/master@{#427146}
(cherry picked from commit 53546e297f782849d9da8004508d0b85c2fd931c)
==========

to

==========
Prevent AutoscrollForSelection when selecting text in a fixed-position element.

AutoscrollForSelection is triggered when selecting text and dragging mouse out
of the container. However, we don't want selecting text in a fixed-position
element triggers autoscroll otherwhere. Inside findAutoscrollable, when we find
the object is inside a fixed-position element, we should prevent
AutoscrollForSelection from happening.

BUG=655489

Review-Url: https://codereview.chromium.org/2441683002
Cr-Commit-Position: refs/heads/master@{#427146}
(cherry picked from commit 53546e297f782849d9da8004508d0b85c2fd931c)

Committed:
https://chromium.googlesource.com/chromium/src/+/9021d6508dfddb41393ae8fa2af2...
==========

[majidvp, 2016-10-27 18:31:04]

Committed patchset #1 (id:1) manually as
9021d6508dfddb41393ae8fa2af2e6dae8cac676.