mash: Migrate ShelfLayoutManager ScreenUtil usage to ash common types.

ash/common/wm/wm_screen_util.h

Index: ash/common/wm/wm_screen_util.h
diff --git a/ash/common/wm/wm_screen_util.h b/ash/common/wm/wm_screen_util.h
index 6ba858aca4eed5113d9c8b4bea776b1e5539eebe..6d0988d0c3dad1ca0130c084d6c273d8a1d8ab87 100644
--- a/ash/common/wm/wm_screen_util.h
+++ b/ash/common/wm/wm_screen_util.h
@@ -22,6 +22,15 @@ ASH_EXPORT gfx::Rect GetDisplayWorkAreaBounds(WmWindow* window);
 ASH_EXPORT gfx::Rect GetDisplayBoundsInParent(WmWindow* window);
 ASH_EXPORT gfx::Rect GetMaximizedWindowBoundsInParent(WmWindow* window);
 
+// Returns the physical display bounds containing the shelf that
+// shares the same display as |window|. Physical displays can
+// differ from logical displays in unified desktop mode.
+// TODO(oshima): If we need to expand the unified desktop support to
+// general use, we should consider always using physical display in
+// window layout instead of root window, and keep the logical
+// display only in display management code.
+ASH_EXPORT gfx::Rect GetShelfDisplayBoundsForWindow(WmWindow* window);

[James Cook, 2016/08/05 23:51:25]

nit: I think this should be renamed to something like
GetDisplayBoundsWithShelf(WmWindow* context) or
GetDisplayBoundsWithShelfForWindow(). I keep thinking it has to do with the
shelf's bounds, and it doesn't.

[msw, 2016/08/06 00:08:13]

Done. I revised the comment too.

+
 }  // namespace wm
 }  // namespace ash