Merge branch 'eng/1400' into wpe-2.38

When I applied the suggested patch upstream I saw that there was some part of
the code that was already upstream from another patch, so I backported both as
part of the fix for this.

Source/WebCore/Modules/modern-media-controls/controls/media-controls.js

@@ -248,4 +248,16 @@ class MediaControls extends LayoutNode
         else
             super.commitProperty(propertyName);
     }
+
+    disable()
+    {
+        this.element.removeEventListener("focusin", this);
+        window.removeEventListener("dragstart", this, true);
+    }
+
+    reenable()
+    {
+        this.element.addEventListener("focusin", this);
+        window.addEventListener("dragstart", this, true);
+    }
 }

Source/WebCore/Modules/modern-media-controls/media/media-controller.js

@@ -222,6 +222,9 @@ class MediaController
     deinitialize()
     {
         this.shadowRoot.removeChild(this.container);
+        window.removeEventListener("keydown", this);
+        if (this.controls)
+            this.controls.disable();
         return true;
     }
 
@@ -232,6 +235,9 @@ class MediaController
         this.mediaWeakRef = new WeakRef(media);
         this.host = host;
         shadowRoot.appendChild(this.container);
+        window.addEventListener("keydown", this);
+        if (this.controls)
+            this.controls.reenable();
         return true;
     }
 
@@ -269,6 +275,9 @@ class MediaController
                 supportingObject.disable();
         }
 
+        if (previousControls)
+            previousControls.disable();
+
         this.controls = new ControlsClass;
         this.controls.delegate = this;