Do the early return when role is different than UnknownRole

Do the early return when role is different than UnknownRole

We do not need to call ariaRoleAttribute() to check whether current role
is different than UnknownRole. Just check m_ariaRole instead.

BUG=

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=186527

[dmazzoni, 2014-12-04 16:44:12]

dmazzoni@chromium.org changed reviewers:
+ dmazzoni@chromium.org

[dmazzoni, 2014-12-04 16:44:12]

The CQ bit was checked by dmazzoni@chromium.org

[dmazzoni, 2014-12-04 16:44:13]

lgtm

[commit-bot: I haz the power, 2014-12-04 16:45:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/756823004/1

[commit-bot: I haz the power, 2014-12-04 17:51:01]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=186527

[dominicc (has gone to gerrit), 2014-12-05 05:00:28]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/773213003/ by dominicc@chromium.org.

The reason for reverting is: Two Nexus 4 tests started crashing after this
change:

ast/animation/request-animation-frame-callback-id.html
svg/canvas/canvas-pattern-svg.html

See eg

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=fas...

First failure is here:

http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Android%20%28Ne...

However the Nexus 4 bot is exhibiting other problems from build 23691 that might
be related. So this is a speculative rollout..

[k.czech, 2014-12-05 11:03:51]

On 2014/12/05 05:00:28, dominicc wrote:
> A revert of this CL (patchset #1 id:1) has been created in
> https://codereview.chromium.org/773213003/ by mailto:dominicc@chromium.org.
> 
> The reason for reverting is: Two Nexus 4 tests started crashing after this
> change:
> 
> ast/animation/request-animation-frame-callback-id.html
> svg/canvas/canvas-pattern-svg.html
> 
> See eg
> 
>
http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=fas...
> 
> First failure is here:
> 
>
http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Android%20%28Ne...
> 
> However the Nexus 4 bot is exhibiting other problems from build 23691 that
might
> be related. So this is a speculative rollout..

It's strange, this change is rather small refactoring in accessibility module.
It should not have any negative impact on those aforementioned tests.