Remove unneeded and incorrect static_cast in AXMediaControlsContainer::controllingVideoElement

There would be no functional changes or performance impacts from
this fix, but this can avoid potential misuses and UBsan's bad-casting reports.

BUG=280225
R=dmazzoni@chromium.org,inferno@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=177407

[inferno, 2014-07-02 03:58:34]

Dominic, since this is accessibility related, can you please this.

[inferno, 2014-07-02 03:58:48]

On 2014/07/02 03:58:34, inferno wrote:
> Dominic, since this is accessibility related, can you please this.

s/please this/please review this.

[inferno, 2014-07-02 15:49:17]

not lgtm

https://codereview.chromium.org/361563003/diff/1/Source/core/accessibility/AX...
File Source/core/accessibility/AXMediaControls.cpp (right):

https://codereview.chromium.org/361563003/diff/1/Source/core/accessibility/AX...
Source/core/accessibility/AXMediaControls.cpp:214: MediaControlDivElement*
element = static_cast<MediaControlDivElement*>(m_renderer->node());
Why do we need a static_cast at all, why not just pass m_renderer->node() to
toParentMediaElement which accepts Node*

[aarya, 2014-07-02 16:25:10]

lgtm

[inferno, 2014-07-02 16:25:36]

lgtm

lgtiming from the chromium account.

[commit-bot: I haz the power, 2014-07-02 16:25:50]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/byoungyoung@chromium.org/361563003/10001

[commit-bot: I haz the power, 2014-07-02 17:46:44]

Change committed as 177407