https://bugs.webkit.org/show_bug.cgi?id=123986

Reviewed by Mario Sanchez Prada.

Though there is toAccessibilityRenderObject(), static_cast<> are being used by many places.
To use toAccessibilityRenderObject() is more helpful to find bad type cast.

No new tests, no behavior changes.

* accessibility/AXObjectCache.cpp:
(WebCore::AXObjectCache::notificationPostTimerFired):
* accessibility/AccessibilityImageMapLink.cpp:
(WebCore::AccessibilityImageMapLink::imageMapLinkRenderer):
* accessibility/AccessibilityRenderObject.cpp:
(WebCore::AccessibilityRenderObject::handleActiveDescendantChanged):
(WebCore::AccessibilityRenderObject::inheritsPresentationalRole):
* accessibility/ios/AccessibilityObjectIOS.mm:
(WebCore::AccessibilityObject::accessibilityPasswordFieldLength):
* accessibility/mac/WebAccessibilityObjectWrapperMac.mm:
(AXAttributeStringSetElement):
(-[WebAccessibilityObjectWrapper accessibilityAttributeValue:]):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@158844 268f45cc-cd09-0410-ab3c-d52691b4dbfc