Dartifying dart:html type names.

sdk/lib/html/templates/html/dart2js/indexed_db_dart2js.darttemplate

Index: sdk/lib/html/templates/html/dart2js/indexed_db_dart2js.darttemplate
diff --git a/sdk/lib/html/templates/html/dart2js/indexed_db_dart2js.darttemplate b/sdk/lib/html/templates/html/dart2js/indexed_db_dart2js.darttemplate
index d55f7c7fdd752e039ed0bcbf86dc79ac76ffd5c7..53145eaca51b17224e837a35c1a4c914fb3e0e03 100644
--- a/sdk/lib/html/templates/html/dart2js/indexed_db_dart2js.darttemplate
+++ b/sdk/lib/html/templates/html/dart2js/indexed_db_dart2js.darttemplate
@@ -58,6 +58,23 @@ class _KeyRangeFactoryProvider {
           cls, lower, upper, lowerOpen, upperOpen);
 }
 
+// Conversions for IDBKey.
+//
+// Per http://www.w3.org/TR/IndexedDB/#key-construct
+//
+// "A value is said to be a valid key if it is one of the following types: Array
+// JavaScript objects [ECMA-262], DOMString [WEBIDL], Date [ECMA-262] or float
+// [WEBIDL]. However Arrays are only valid keys if every item in the array is
+// defined and is a valid key (i.e. sparse arrays can not be valid keys) and if
+// the Array doesn't directly or indirectly contain itself. Any non-numeric
+// properties are ignored, and thus does not affect whether the Array is a valid
+// key. Additionally, if the value is of type float, it is only a valid key if
+// it is not NaN, and if the value is of type Date it is only a valid key if its
+// [[PrimitiveValue]] internal property, as defined by [ECMA-262], is not NaN."
+
+// What is required is to ensure that an Lists in the key are actually
+// JavaScript arrays, and any Dates are JavaScript Dates.
+
 
 /**
  * Converts a native IDBKey into a Dart object.