cleanup: Mark unused arguments as unused

This will stop eslint from warning about them, while keeping their
self-documenting benefit.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/627

js/ui/workspace.js

@@ -72,11 +72,11 @@ class WindowCloneLayout extends Clutter.LayoutManager {
         return box;
     }
 
-    vfunc_get_preferred_height(container, forWidth) {
+    vfunc_get_preferred_height(_container, _forWidth) {
         return [this._boundingBox.height, this._boundingBox.height];
     }
 
-    vfunc_get_preferred_width(container, forHeight) {
+    vfunc_get_preferred_width(_container, _forHeight) {
         return [this._boundingBox.width, this._boundingBox.width];
     }
 
@@ -403,7 +403,7 @@ var WindowClone = GObject.registerClass({
         return true;
     }
 
-    _onDragBegin(draggable, time) {
+    _onDragBegin(_draggable, _time) {
         this._dragSlot = this._slot;
         [this.dragOrigX, this.dragOrigY] = this.get_position();
         this.dragOrigScale = this.scale_x;
@@ -419,11 +419,11 @@ var WindowClone = GObject.registerClass({
         this._workspace.acceptDrop(source, actor, x, y, time);
     }
 
-    _onDragCancelled(draggable, time) {
+    _onDragCancelled(_draggable, _time) {
         this.emit('drag-cancelled');
     }
 
-    _onDragEnd(draggable, time, snapback) {
+    _onDragEnd(_draggable, _time, _snapback) {
         this.inDrag = false;
 
         // We may not have a parent if DnD completed successfully, in
@@ -845,7 +845,7 @@ var LayoutStrategy = class {
     // row.width, row.height, row.fullWidth, row.fullHeight, and
     // (optionally) for each row in @layout.rows. This method is
     // intended to be called by subclasses.
-    _computeRowSizes(layout) {
+    _computeRowSizes(_layout) {
         throw new GObject.NotImplementedError(`_computeRowSizes in ${this.constructor.name}`);
     }
 
@@ -858,7 +858,7 @@ var LayoutStrategy = class {
     //  * gridWidth - The total width used by the grid, unscaled, unspaced.
     //  * gridHeight - The totial height used by the grid, unscaled, unspaced.
     //  * rows - A list of rows, which should be instantiated by _newRow.
-    computeLayout(windows, layout) {
+    computeLayout(_windows, _layout) {
         throw new GObject.NotImplementedError(`computeLayout in ${this.constructor.name}`);
     }
 
@@ -1979,7 +1979,7 @@ var Workspace = class {
     }
 
     // Draggable target interface
-    handleDragOver(source, actor, x, y, time) {
+    handleDragOver(source, _actor, _x, _y, _time) {
         if (source.realWindow && !this._isMyWindow(source.realWindow))
             return DND.DragMotionResult.MOVE_DROP;
         if (source.shellWorkspaceLaunch)