Low risk non-nullable => nullable change

third_party/WebKit/Source/modules/webmidi/MIDIPort.idl

Index: third_party/WebKit/Source/modules/webmidi/MIDIPort.idl
diff --git a/third_party/WebKit/Source/modules/webmidi/MIDIPort.idl b/third_party/WebKit/Source/modules/webmidi/MIDIPort.idl
index d3523bfb9ea9ee449f11f453fe06637ca94c1cc7..e88f6ae10de8059a9971239391d6c631166a706c 100644
--- a/third_party/WebKit/Source/modules/webmidi/MIDIPort.idl
+++ b/third_party/WebKit/Source/modules/webmidi/MIDIPort.idl
@@ -58,11 +58,11 @@ enum MIDIPortType {
 ] interface MIDIPort : EventTarget {
     readonly attribute MIDIPortConnectionState connection;
     readonly attribute DOMString id;
-    readonly attribute DOMString manufacturer;
-    readonly attribute DOMString name;
+    readonly attribute DOMString? manufacturer;

[foolip, 2016/12/13 22:37:31]

Oh my, I've lied again. This would change the generated code I think, to make
the return value change from "" to null if a null WTF::String is returned.

Maybe it's best to compare the generated code to make sure what will remain
really doesn't change anything.

+    readonly attribute DOMString? name;
     readonly attribute MIDIPortDeviceState state;
     readonly attribute MIDIPortType type;
-    readonly attribute DOMString version;
+    readonly attribute DOMString? version;
 
     attribute EventHandler onstatechange;