Provide a fallback for AudioBufferSourceNode.start to noteOn and stop to

lib/html/templates/html/dart2js/impl_AudioBufferSourceNode.darttemplate

Index: lib/html/templates/html/dart2js/impl_AudioBufferSourceNode.darttemplate
===================================================================
--- lib/html/templates/html/dart2js/impl_AudioBufferSourceNode.darttemplate	(revision 0)
+++ lib/html/templates/html/dart2js/impl_AudioBufferSourceNode.darttemplate	(working copy)
@@ -0,0 +1,25 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
+
+  // TODO(efortuna): Remove these methods when Chrome stable also uses start
+  // instead of noteOn.
+  void start(num when, [num grainOffset, num grainDuration]) {
+    if (JS('bool', '!!#.start', this)) {
+      JS('void', '#.start(#, #, #)', this, when, grainOffset, grainDuration);
+    } else {
+      JS('void', '#.noteOn(#, #, #)', this, when, grainOffset, grainDuration);
+    }
+  }
+
+  void stop(num when) {
+    if (JS('bool', '!!#.stop', this)) {
+      JS('void', '#.stop(#)', this, when);
+    } else {
+      JS('void', '#.noteOff(#)', this, when);
+    }
+  }
+$!MEMBERS
+}