WebScrollbarThemeClientImpl should not be DisplayItemClient

WebScrollbarThemeClientImpl should not be DisplayItemClient

WebScrollbarThemeClientImpl inherited DisplayItemClient from
ScrollbarThemeClient but it is never used as a DisplayItemClient.

Let Scrollbar instead of ScrollbarThemeClient inherit
DisplayItemClient, and use Scrollbar type in ScrollbarTheme
paint methods.

This avoids the need to let WebScrollbarThemeClientImpl follow
the rules of DisplayItemClient caching.

Committed: https://crrev.com/ac0330544bb3294a5df1aa94fb0cd7c896804e11
Cr-Commit-Position: refs/heads/master@{#398818}

[Xianzhu, 2016-06-07 22:40:51]

Description was changed from

==========
WebScrollbarThemeClientImpl should not be DisplayItemClient

WebScrollbarThemeClientImpl inherits DisplayItemClient from
ScrollbarThemeClient but it is never used as a DisplayItemClient.

Let Scrollbar instead of ScrollbarThemeClient inherit
DisplayItemClient, and use Scrollbar type in ScrollbarTheme
paint methods.

This avoids the need to let WebScrollbarThemeClientImpl follow
the rules of DisplayItemClient caching.
==========

to

==========
WebScrollbarThemeClientImpl should not be DisplayItemClient

WebScrollbarThemeClientImpl inherited DisplayItemClient from
ScrollbarThemeClient but it is never used as a DisplayItemClient.

Let Scrollbar instead of ScrollbarThemeClient inherit
DisplayItemClient, and use Scrollbar type in ScrollbarTheme
paint methods.

This avoids the need to let WebScrollbarThemeClientImpl follow
the rules of DisplayItemClient caching.
==========

[Xianzhu, 2016-06-08 16:35:19]

wangxianzhu@chromium.org changed reviewers:
+ chrishtr@chromium.org

[chrishtr, 2016-06-09 02:08:25]

The CQ bit was checked by chrishtr@chromium.org

[chrishtr, 2016-06-09 02:08:25]

lgtm

[commit-bot: I haz the power, 2016-06-09 02:08:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2045963003/20001

[commit-bot: I haz the power, 2016-06-09 05:34:39]

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

[commit-bot: I haz the power, 2016-06-09 05:34:41]

Try jobs failed on following builders:
  linux_chromium_gn_chromeos_rel on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Xianzhu, 2016-06-09 05:40:58]

The CQ bit was checked by wangxianzhu@chromium.org

[commit-bot: I haz the power, 2016-06-09 05:41:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2045963003/20001

[commit-bot: I haz the power, 2016-06-09 08:55:23]

Description was changed from

==========
WebScrollbarThemeClientImpl should not be DisplayItemClient

WebScrollbarThemeClientImpl inherited DisplayItemClient from
ScrollbarThemeClient but it is never used as a DisplayItemClient.

Let Scrollbar instead of ScrollbarThemeClient inherit
DisplayItemClient, and use Scrollbar type in ScrollbarTheme
paint methods.

This avoids the need to let WebScrollbarThemeClientImpl follow
the rules of DisplayItemClient caching.
==========

to

==========
WebScrollbarThemeClientImpl should not be DisplayItemClient

WebScrollbarThemeClientImpl inherited DisplayItemClient from
ScrollbarThemeClient but it is never used as a DisplayItemClient.

Let Scrollbar instead of ScrollbarThemeClient inherit
DisplayItemClient, and use Scrollbar type in ScrollbarTheme
paint methods.

This avoids the need to let WebScrollbarThemeClientImpl follow
the rules of DisplayItemClient caching.
==========

[commit-bot: I haz the power, 2016-06-09 08:55:24]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-06-09 08:57:07]

Description was changed from

==========
WebScrollbarThemeClientImpl should not be DisplayItemClient

WebScrollbarThemeClientImpl inherited DisplayItemClient from
ScrollbarThemeClient but it is never used as a DisplayItemClient.

Let Scrollbar instead of ScrollbarThemeClient inherit
DisplayItemClient, and use Scrollbar type in ScrollbarTheme
paint methods.

This avoids the need to let WebScrollbarThemeClientImpl follow
the rules of DisplayItemClient caching.
==========

to

==========
WebScrollbarThemeClientImpl should not be DisplayItemClient

WebScrollbarThemeClientImpl inherited DisplayItemClient from
ScrollbarThemeClient but it is never used as a DisplayItemClient.

Let Scrollbar instead of ScrollbarThemeClient inherit
DisplayItemClient, and use Scrollbar type in ScrollbarTheme
paint methods.

This avoids the need to let WebScrollbarThemeClientImpl follow
the rules of DisplayItemClient caching.

Committed: https://crrev.com/ac0330544bb3294a5df1aa94fb0cd7c896804e11
Cr-Commit-Position: refs/heads/master@{#398818}
==========

[commit-bot: I haz the power, 2016-06-09 08:57:08]

Patchset 2 (id:??) landed as
https://crrev.com/ac0330544bb3294a5df1aa94fb0cd7c896804e11
Cr-Commit-Position: refs/heads/master@{#398818}