Optimize dartium dart:html bindings so real world application performance is acceptable. Improves d…

tools/dom/templates/html/dartium/indexed_db_dartium.darttemplate

Index: tools/dom/templates/html/dartium/indexed_db_dartium.darttemplate
diff --git a/tools/dom/templates/html/dartium/indexed_db_dartium.darttemplate b/tools/dom/templates/html/dartium/indexed_db_dartium.darttemplate
index ef3928c9988eb73de4db3deed21b378b6cc98adf..dee0cace7878aa865dfd442d4052f9f20cd9495a 100644
--- a/tools/dom/templates/html/dartium/indexed_db_dartium.darttemplate
+++ b/tools/dom/templates/html/dartium/indexed_db_dartium.darttemplate
@@ -112,10 +112,66 @@ final indexed_dbBlinkMap = {
 $!TYPE_MAP
 };
 
-$if JSINTEROP
-// FIXME: Can we make this private?
-@Deprecated("Internal Use Only")
-final indexed_dbBlinkFunctionMap = {
-$!TYPE_FUNCTION_MAP
-};
-$endif
+
+//
+// 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.
+ *
+ * May return the original input.  May mutate the original input (but will be
+ * idempotent if mutation occurs).  It is assumed that this conversion happens
+ * on native IDBKeys on all paths that return IDBKeys from native DOM calls.
+ *
+ * If necessary, JavaScript Dates are converted into Dart Dates.
+ */
+_convertNativeToDart_IDBKey(nativeKey) {
+  containsDate(object) {
+    if (object is DateTime) return true;
+    if (object is List) {
+      for (int i = 0; i < object.length; i++) {
+        if (containsDate(object[i])) return true;
+      }
+    }
+    return false;  // number, string.
+  }
+  if (nativeKey is DateTime) {
+    throw new UnimplementedError('Key containing DateTime');
+  }
+  // TODO: Cache conversion somewhere?
+  return nativeKey;
+}
+
+/**
+ * Converts a Dart object into a valid IDBKey.
+ *
+ * May return the original input.  Does not mutate input.
+ *
+ * If necessary, [dartKey] may be copied to ensure all lists are converted into
+ * JavaScript Arrays and Dart Dates into JavaScript Dates.
+ */
+_convertDartToNative_IDBKey(dartKey) {
+  // TODO: Implement.
+  return dartKey;
+}
+
+
+
+/// May modify original.  If so, action is idempotent.
+_convertNativeToDart_IDBAny(object) {
+  return convertNativeToDart_AcceptStructuredClone(object, mustCopy: false);
+}