First half of the new HTML json docs.

utils/apidoc/lib/metadata.dart

+library metadata;
+
+import '../../../sdk/lib/_internal/compiler/implementation/mirrors/mirrors.dart';
+
+/// Returns the metadata for the given string or null if not found.
+InstanceMirror findMetadata(List<InstanceMirror> metadataList, String find) {
+  return metadataList.firstMatching(
+      (metadata) {
+        if (metadata is TypeInstanceMirror) {
+          return metadata.representedType.simpleName == find;
+        }
+        return metadata.type.simpleName == find;
+      }, orElse: () => null);
+}