Removes most aura dependencies from WindowResizer

ash/wm/common/root_window_finder.cc

Index: ash/wm/common/root_window_finder.cc
diff --git a/ash/wm/coordinate_conversion.cc b/ash/wm/common/root_window_finder.cc
similarity index 50%
rename from ash/wm/coordinate_conversion.cc
rename to ash/wm/common/root_window_finder.cc
index e591f3f1b6e8b664307a6c4d2cfbcfc207c93f33..69b2f99da6afce035395b49ef5f6e963f812a48e 100644
--- a/ash/wm/coordinate_conversion.cc
+++ b/ash/wm/common/root_window_finder.cc
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ash/wm/coordinate_conversion.h"
+#include "ash/wm/common/root_window_finder.h"
 
 #include "ash/display/window_tree_host_manager.h"
-#include "ash/shell.h"
-#include "ui/aura/client/screen_position_client.h"
+#include "ash/wm/common/wm_root_window_controller.h"
+#include "ash/wm/common/wm_window.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
@@ -15,23 +15,21 @@
 namespace ash {
 namespace wm {
 
-aura::Window* GetRootWindowAt(const gfx::Point& point) {
+WmWindow* GetRootWindowAt(const gfx::Point& point) {
   const gfx::Display& display =
       gfx::Screen::GetScreen()->GetDisplayNearestPoint(point);
   DCHECK(display.is_valid());
-  // TODO(yusukes): Move coordinate_conversion.cc and .h to ui/aura/ once
-  // GetRootWindowForDisplayId() is moved to aura::Env.
-  return Shell::GetInstance()
-      ->window_tree_host_manager()
-      ->GetRootWindowForDisplayId(display.id());
+  WmRootWindowController* root_window_controller =
+      WmRootWindowController::GetWithDisplayId(display.id());
+  return root_window_controller ? root_window_controller->GetWindow() : nullptr;
 }
 
-aura::Window* GetRootWindowMatching(const gfx::Rect& rect) {
+WmWindow* GetRootWindowMatching(const gfx::Rect& rect) {
   const gfx::Display& display =
       gfx::Screen::GetScreen()->GetDisplayMatching(rect);
-  return Shell::GetInstance()
-      ->window_tree_host_manager()
-      ->GetRootWindowForDisplayId(display.id());
+  WmRootWindowController* root_window_controller =
+      WmRootWindowController::GetWithDisplayId(display.id());
+  return root_window_controller ? root_window_controller->GetWindow() : nullptr;
 }
 
 }  // namespace wm