Prevent context menu from flickering after FocusableNode redraw

Pass an extra parameter to show() to let it know when the menu is
just being moved, and therefore doesn't need to perform the fade-in
transition.

Change-Id: I2cf2ff07db6cc7d226f3d626755792a06dfcbe54
Merge "Prevent context menu from flickering after FocusableNode redraw"