Add live region root to the cached properties of an AXObject.

Source/core/accessibility/AXRenderObject.h

Index: Source/core/accessibility/AXRenderObject.h
diff --git a/Source/core/accessibility/AXRenderObject.h b/Source/core/accessibility/AXRenderObject.h
index a447d3c296feefe52e98889717cebab9fcf6d29b..cfe4f851ca7606278b4f40692ef66db1c7bdf705 100644
--- a/Source/core/accessibility/AXRenderObject.h
+++ b/Source/core/accessibility/AXRenderObject.h
@@ -126,10 +126,10 @@ protected:
     virtual bool supportsARIAOwns() const override;
 
     // ARIA live-region features.
-    virtual const AtomicString& ariaLiveRegionStatus() const override;
-    virtual const AtomicString& ariaLiveRegionRelevant() const override;
-    virtual bool ariaLiveRegionAtomic() const override;
-    virtual bool ariaLiveRegionBusy() const override;
+    virtual const AtomicString& liveRegionStatus() const override;
+    virtual const AtomicString& liveRegionRelevant() const override;
+    virtual bool liveRegionAtomic() const override;
+    virtual bool liveRegionBusy() const override;
 
     // Accessibility Text.
     virtual String textUnderElement() const override;