LibWeb: Add ConstantSourceNode interface

Author: https://github.com/tcl3
Commit: 1b160044c4
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3102
Reviewed-by: https://github.com/shannonbooth

Libraries/LibWeb/WebAudio/ConstantSourceNode.idl

@@ -0,0 +1,15 @@
+#import <WebAudio/AudioNode.idl>
+#import <WebAudio/AudioParam.idl>
+#import <WebAudio/BaseAudioContext.idl>
+
+// https://webaudio.github.io/web-audio-api/#ConstantSourceOptions
+dictionary ConstantSourceOptions {
+    float offset = 1;
+};
+
+// https://webaudio.github.io/web-audio-api/#ConstantSourceNode
+[Exposed=Window]
+interface ConstantSourceNode : AudioScheduledSourceNode {
+    constructor (BaseAudioContext context, optional ConstantSourceOptions options = {});
+    readonly attribute AudioParam offset;
+};