Remove WmLookup.

ash/common/wm/workspace/workspace_window_resizer.cc

Index: ash/common/wm/workspace/workspace_window_resizer.cc
diff --git a/ash/common/wm/workspace/workspace_window_resizer.cc b/ash/common/wm/workspace/workspace_window_resizer.cc
index bee0bb465bbc43dc61e7894ec244b06f7b367fbd..5f66ec57fd572e0d84222001b04f1f4081818698 100644
--- a/ash/common/wm/workspace/workspace_window_resizer.cc
+++ b/ash/common/wm/workspace/workspace_window_resizer.cc
@@ -21,11 +21,11 @@
 #include "ash/common/wm/wm_screen_util.h"
 #include "ash/common/wm/workspace/phantom_window_controller.h"
 #include "ash/common/wm/workspace/two_step_edge_cycler.h"
-#include "ash/common/wm_lookup.h"
 #include "ash/common/wm_shell.h"
 #include "ash/common/wm_window.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/root_window_controller.h"
+#include "ash/shell.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
 #include "ui/base/hit_test.h"
@@ -365,9 +365,8 @@ void WorkspaceWindowResizer::Drag(const gfx::Point& location_in_parent,
   // Track the last screen that the pointer was on to keep the snap phantom
   // window there.
   if (display.bounds().Contains(location_in_screen)) {
-    root = WmLookup::Get()
-               ->GetRootWindowControllerWithDisplayId(display.id())
-               ->GetWindow();
+    root =
+        Shell::GetRootWindowControllerWithDisplayId(display.id())->GetWindow();
   }
   if (!attached_windows_.empty())
     LayoutAttachedWindows(&bounds);