Don't use => on void functions.

tools/dom/templates/html/impl/impl_AudioNode.darttemplate

Index: tools/dom/templates/html/impl/impl_AudioNode.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_AudioNode.darttemplate b/tools/dom/templates/html/impl/impl_AudioNode.darttemplate
index 43db4b3ec890e678229b7aff458e9ee2de590eb9..e5ba37a0152c2cc67734a39fa9a72d95eb873310 100644
--- a/tools/dom/templates/html/impl/impl_AudioNode.darttemplate
+++ b/tools/dom/templates/html/impl/impl_AudioNode.darttemplate
@@ -7,10 +7,12 @@ part of web_audio;
 $(ANNOTATIONS)$(NATIVESPEC)class $CLASSNAME$EXTENDS$IMPLEMENTS {
 $!MEMBERS
   @DomName('AudioNode.connect')
-  void connectNode(AudioNode destination, [int output = 0, int input = 0]) =>
-      _connect(destination, output, input);
+  void connectNode(AudioNode destination, [int output = 0, int input = 0]) {
+    _connect(destination, output, input);
+  }
 
   @DomName('AudioNode.connect')
-  void connectParam(AudioParam destination, [int output = 0]) =>
-      _connect(destination, output);
+  void connectParam(AudioParam destination, [int output = 0]) {
+    _connect(destination, output);
+  }
 }