This introduces styles for "not available" arrow, and styles for hovered arrow
and "active" (under left mouse button click arrow).
Bug: T135970
Change-Id: If5f7df475eef36dcb6d038297ad97717b8c96f77
This also allows pointer to be dragged past the other. In such case
pointer colour changes while dragging, but pointer orientation/position
is only updated after dragging is finished (along with reloading diff etc).
Bug: T134994
Bug: T134996
Change-Id: Ia333306b5b0a488a4f8e92ac4b1b843dc4863d47
Pointer shadow is left out here on purpose. It will be
added after changing "new" pointer's position.
Bug: T134994
Change-Id: Id80ed63cda9f015228a22bb1d8b9b742438fe27d