[Contextual Search] Remove layers when no longer needed.

[Contextual Search] Remove layers when no longer needed.

Now that there can be multiple Overlays Panels being used,
a few bugs are happening due to the Panel's cc::Layer not
being properly removed.

This CL fixes the problem by removing the layer when a
OverlayPanel shows up when another one is being displayed.

Also, this CL removed the OverlayPanel layer from the
StaticLayout whenever that layout gets hidden (see
dettachViews method).

BUG=539847
Review URL: https://codereview.chromium.org/1489213002

Cr-Commit-Position: refs/heads/master@{#363092}
(cherry picked from commit a53e46eff945b879f6e72108073d3d70d47d6b0e)

Committed: https://chromium.googlesource.com/chromium/src/+/a9c0375ea30b080e06f8d5f646e8b31e43c42608

[pedro (no code reviews), 2015-12-04 23:08:24]

Description was changed from

==========
[Contextual Search] Remove layers when no longer needed.

Now that there can be multiple Overlays Panels being used,
a few bugs are happening due to the Panel's cc::Layer not
being properly removed.

This CL fixes the problem by removing the layer when a
OverlayPanel shows up when another one is being displayed.

Also, this CL removed the OverlayPanel layer from the
StaticLayout whenever that layout gets hidden (see
dettachViews method).

BUG=539847

Review URL: https://codereview.chromium.org/1489213002

Cr-Commit-Position: refs/heads/master@{#363092}
(cherry picked from commit a53e46eff945b879f6e72108073d3d70d47d6b0e)
==========

to

==========
[Contextual Search] Remove layers when no longer needed.

Now that there can be multiple Overlays Panels being used,
a few bugs are happening due to the Panel's cc::Layer not
being properly removed.

This CL fixes the problem by removing the layer when a
OverlayPanel shows up when another one is being displayed.

Also, this CL removed the OverlayPanel layer from the
StaticLayout whenever that layout gets hidden (see
dettachViews method).

BUG=539847

Review URL: https://codereview.chromium.org/1489213002

Cr-Commit-Position: refs/heads/master@{#363092}
(cherry picked from commit a53e46eff945b879f6e72108073d3d70d47d6b0e)

Committed:
https://chromium.googlesource.com/chromium/src/+/a9c0375ea30b080e06f8d5f646e8...
==========

[pedro (no code reviews), 2015-12-04 23:08:25]

Committed patchset #1 (id:1) manually as
a9c0375ea30b080e06f8d5f646e8b31e43c42608 (tree was closed).