We might want to have this behavior also in the crossplatform code.
+++ This bug was initially created as a clone of Bug #137805 +++
The volume slider in the built-in media controls doesn’t change the volume continuously as the thumb is being dragged. Instead, volume only changes when it’s released.
To reproduce: navigate to the URL. When music starts playing, hover over the volume button in the media controls, then click and hold the thumb in the volume slider, and while still holding, drag it downwards. Notice that the volume doesn’t decrease. Release the thumb and notice that the volume drops.
This is a regression, caused by <http://trac.webkit.org/r170808>, the fix for bug 134545.