Roll IDL to Dartium37 (r181268)

modules/webaudio/AudioBuffer.idl

Index: modules/webaudio/AudioBuffer.idl
diff --git a/modules/webaudio/AudioBuffer.idl b/modules/webaudio/AudioBuffer.idl
index 19f66a5f2a0b958dc204be063f3e37c7eea42bb3..7ec7c60bb4cbeed0f1eb99e0a9782705df6d657e 100644
--- a/modules/webaudio/AudioBuffer.idl
+++ b/modules/webaudio/AudioBuffer.idl
@@ -27,14 +27,13 @@
  */
 
 [
+    WillBeGarbageCollected,
     Conditional=WEB_AUDIO
 ] interface AudioBuffer {
     readonly attribute long length; // in sample-frames
-    readonly attribute float duration; // in seconds
+    readonly attribute double duration; // in seconds
     readonly attribute float sampleRate; // in sample-frames per second
 
-    attribute float gain; // linear gain (default 1.0)
-
     // Channel access
     readonly attribute unsigned long numberOfChannels;
     [RaisesException] Float32Array getChannelData(unsigned long channelIndex);