Update programmatic scrolls on the RootFrameViewport.

Update programmatic smooth scrolls on the RootFrameViewport.

Currently, the update occurs on the root FrameView so any programmatic
smooth scrolls on the RootFrameViewport wont get updated. This patch
causes the update to occur on the RootFrameViewport, which updates its
own animations, then calls the root FrameView's update method.

No test as smooth scrolls on RootFrameViewport aren't supported yet.
When that's enabled, any tests on that will implicitly test that
this works.

BUG=434497
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196603

[bokan, 2015-06-03 21:27:01]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[bokan, 2015-06-03 21:27:27]

bokan@chromium.org changed reviewers:
+ vollick@chromium.org

[bokan, 2015-06-03 21:27:27]

ptal.

[commit-bot: I haz the power, 2015-06-03 21:29:08]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1148283011/1

[commit-bot: I haz the power, 2015-06-03 22:10:15]

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

[commit-bot: I haz the power, 2015-06-03 22:10:17]

Dry run: Try jobs failed on following builders:
  linux_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/6...)
  mac_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/57559)

[Ian Vollick, 2015-06-05 17:56:46]

On 2015/06/03 at 22:10:17, commit-bot wrote:
> Dry run: Try jobs failed on following builders:
>   linux_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/6...)
>   mac_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/57559)

lgtm

[bokan, 2015-06-05 17:57:46]

The CQ bit was checked by bokan@chromium.org

[commit-bot: I haz the power, 2015-06-05 17:58:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1148283011/1

[commit-bot: I haz the power, 2015-06-05 20:27:16]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196603