Changed the point for searching clickable node to get focus ring rect.

Changed the point for searching clickable node to get focus ring rect.

[Title] Changed the point for searching clickable node to get focus ring rect.
[Issue#] DCM-2047
[Problem] focus ring is displayed above two link menu than tapped link menu.
[Cause] When user tap contents in iframe, it is searching clickable node using the point from iframe.
        But, the point from main frame is needed for searching clickable node.
        So, focus ring is displayed at wrong position.
[Solution] Changed the point for searching clickable node to the main frame point.

Change-Id: I9df118900b39aefdb0671bd167acc91beea4b582