Use WindowManager instead of WindowManagerGala where possible (#2867)

Author: leolost2605

src/BlurManager.vala

@@ -18,7 +18,7 @@ public class Gala.BlurManager : Object {
 
     private static BlurManager instance;
 
-    public static void init (WindowManagerGala wm) {
+    public static void init (WindowManager wm) {
         if (instance != null) {
             return;
         }
@@ -30,11 +30,11 @@ public class Gala.BlurManager : Object {
         return instance;
     }
 
-    public WindowManagerGala wm { get; construct; }
+    public WindowManager wm { get; construct; }
 
     private GLib.HashTable<Meta.Window, BlurData?> blurred_windows = new GLib.HashTable<Meta.Window, BlurData?> (null, null);
 
-    private BlurManager (WindowManagerGala wm) {
+    private BlurManager (WindowManager wm) {
         Object (wm: wm);
     }
 

src/Widgets/MultitaskingView/MultitaskingView.vala

@@ -28,7 +28,7 @@ public class Gala.MultitaskingView : Root, RootTarget, ActivatableComponent {
     private GestureController multitasking_gesture_controller;
 
     public Clutter.Actor? actor { get { return this; } }
-    public WindowManagerGala wm { get; construct; }
+    public WindowManager wm { get; construct; }
 
     private Meta.Display display;
     private ModalProxy modal_proxy;
@@ -51,7 +51,7 @@ public class Gala.MultitaskingView : Root, RootTarget, ActivatableComponent {
     private Clutter.PanAction pan_action;
 #endif
 
-    public MultitaskingView (WindowManagerGala wm) {
+    public MultitaskingView (WindowManager wm) {
         Object (wm: wm);
     }