Remove window/host accessors from WED; IWYU for WTH

ui/views/widget/desktop_aura/x11_desktop_window_move_client.h

Index: ui/views/widget/desktop_aura/x11_desktop_window_move_client.h
diff --git a/ui/views/widget/desktop_aura/x11_desktop_window_move_client.h b/ui/views/widget/desktop_aura/x11_desktop_window_move_client.h
index 935ffcd6e2fb4d6a74f4300fd83fc00975889b55..12e5928c0fe65413fa4adddadb5c2df12552cfa2 100644
--- a/ui/views/widget/desktop_aura/x11_desktop_window_move_client.h
+++ b/ui/views/widget/desktop_aura/x11_desktop_window_move_client.h
@@ -18,7 +18,7 @@
 #include "ui/views/widget/desktop_aura/x11_whole_screen_move_loop_delegate.h"
 
 namespace aura {
-class WindowEventDispatcher;
+class WindowTreeHost;
 }
 
 namespace gfx {
@@ -55,7 +55,7 @@ class VIEWS_EXPORT X11DesktopWindowMoveClient :
 
   // We need to keep track of this so we can actually move it when reacting to
   // mouse events.
-  aura::WindowEventDispatcher* dispatcher_;
+  aura::WindowTreeHost* host_;
 
   // Our cursor offset from the top left window origin when the drag
   // started. Used to calculate the window's new bounds relative to the current