Updated so that any Dart change to an IDL file has // FIXMEDART: comment

TBR=jacobr@google.com

Review-Url: https://codereview.chromium.org//2753323002 .
diff --git a/bindings/scripts/idl_reader.py b/bindings/scripts/idl_reader.py
index f0952f0..f406c00 100644
--- a/bindings/scripts/idl_reader.py
+++ b/bindings/scripts/idl_reader.py
@@ -75,6 +75,7 @@
 
 
 class IdlReader(object):
+    # FIXMEDART: Added multi_interface argument and property for IdlReader class.
     def __init__(self, interfaces_info=None, outputdir='', multi_interface=False):
         self.multi_interface = multi_interface
         self.extended_attribute_validator = IDLExtendedAttributeValidator()
@@ -114,6 +115,7 @@
         idl_file_basename, _ = os.path.splitext(os.path.basename(idl_filename))
         definitions = IdlDefinitions(idl_file_basename, ast)
 
+        # FIXMEDART: Added multi_interface.
         if not self.multi_interface:
             validate_blink_idl_definitions(idl_filename, idl_file_basename, definitions)
         else:
diff --git a/core/frame/NavigatorID.idl b/core/frame/NavigatorID.idl
index 406863e..eeeeba4 100644
--- a/core/frame/NavigatorID.idl
+++ b/core/frame/NavigatorID.idl
@@ -43,5 +43,6 @@
     // boolean taintEnabled(); // constant false
     readonly attribute DOMString userAgent;
 
+    // FIXMEDART: Added for Dart
     readonly attribute boolean dartEnabled;
 };