Get rid of custom bindings for AudioContext's constructor

Source/modules/webaudio/AudioContext.idl

Index: Source/modules/webaudio/AudioContext.idl
diff --git a/Source/modules/webaudio/AudioContext.idl b/Source/modules/webaudio/AudioContext.idl
index b7a8598ac297ed45543e3dd2dbf6bfe2140666ea..f14e8b6e551d3a211aae303711686287df4a5cb2 100644
--- a/Source/modules/webaudio/AudioContext.idl
+++ b/Source/modules/webaudio/AudioContext.idl
@@ -27,7 +27,10 @@
     NoInterfaceObject,
     Conditional=WEB_AUDIO,
     ActiveDOMObject,
-    CustomConstructor
+    Constructor,
+    Constructor(unsigned long numberOfChannels, unsigned long numberOfFrames, float sampleRate),
+    ConstructorCallWith=Document,
+    ConstructorRaisesException
 ] interface AudioContext : EventTarget {
     // All rendered audio ultimately connects to destination, which represents the audio hardware.
     readonly attribute AudioDestinationNode destination;