Update IDL to Chrome 32

modules/webaudio/AudioBufferSourceNode.idl

Index: modules/webaudio/AudioBufferSourceNode.idl
diff --git a/modules/webaudio/AudioBufferSourceNode.idl b/modules/webaudio/AudioBufferSourceNode.idl
index 24c95eb3b2fbd93ce11b8be8c1c9bd05efa5d766..946b28b122fcfd5ed9c784b7b643d77989d0729f 100644
--- a/modules/webaudio/AudioBufferSourceNode.idl
+++ b/modules/webaudio/AudioBufferSourceNode.idl
@@ -26,7 +26,7 @@
 [
     Conditional=WEB_AUDIO
 ] interface AudioBufferSourceNode : AudioSourceNode {
-    [CustomSetter, SetterRaisesException] attribute AudioBuffer buffer;
+    [StrictTypeChecking, SetterRaisesException] attribute AudioBuffer buffer;
 
     const unsigned short UNSCHEDULED_STATE = 0;
     const unsigned short SCHEDULED_STATE = 1;
@@ -43,16 +43,14 @@
     attribute double loopStart;
     attribute double loopEnd;
 
-    [MeasureAs=WebAudioStart] void start(double when);
-    [MeasureAs=WebAudioStart, ImplementedAs=startGrain] void start(double when, double grainOffset);
-    [MeasureAs=WebAudioStart, ImplementedAs=startGrain] void start(double when, double grainOffset, double grainDuration);
-    void stop(double when);
+    [RaisesException, MeasureAs=WebAudioStart] void start(optional double when, optional double grainOffset, optional double grainDuration);
+    [RaisesException] void stop(optional double when);
 
     [DeprecateAs=WebAudioLooping, ImplementedAs=loop] attribute boolean looping; // This is an alias for the .loop attribute for backwards compatibility.
 
-    [MeasureAs=LegacyWebAudio] void noteOn(double when);
-    [MeasureAs=LegacyWebAudio] void noteGrainOn(double when, double grainOffset, double grainDuration);
-    void noteOff(double when);
+    [RaisesException, ImplementedAs=start, MeasureAs=LegacyWebAudio] void noteOn(double when);
+    [RaisesException, MeasureAs=LegacyWebAudio] void noteGrainOn(double when, double grainOffset, double grainDuration);
+    [RaisesException, ImplementedAs=stop] void noteOff(double when);
 
     attribute EventHandler onended;
 };