Fix for the issue "context menu is not shown on selecting selectall on contextmenu"

Fix for the issue "context menu is not shown on selecting selectall on contextmenu"

[Title]  Fix for the issue context menu is not shown on selecting selectall on contextmenu
[Issue#] Web-3918
[Problem] Context menu is not displaying
[Cause]  Lectrect handler was not properly checked with Viewport rect
         If LeftRect's handler x & y position is in border of viewport maxX and maxY position, this was not handled.
[Solution] Made proper check for leftRect handlers wrt ViewRect.

Change-Id: Ibc1c528d6be838a7dc68f63b87ee396370fd3397