update one-line docs for svg, gl, audio

sdk/lib/svg/dartium/svg_dartium.dart

Index: sdk/lib/svg/dartium/svg_dartium.dart
diff --git a/sdk/lib/svg/dartium/svg_dartium.dart b/sdk/lib/svg/dartium/svg_dartium.dart
index 63a74c64146d8fd9db139fc2263c619ad0a0b9fd..0090a4d0bfb0d6c5333358adaef88b3ae6ea9426 100644
--- a/sdk/lib/svg/dartium/svg_dartium.dart
+++ b/sdk/lib/svg/dartium/svg_dartium.dart
@@ -1,3 +1,11 @@
+/**
+ * Scalable Vector Graphics:
+ * Two-dimensional vector graphics with support for events and animation.
+ *
+ * For details about the features and syntax of SVG, a W3C standard,
+ * refer to the
+ * [Scalable Vector Graphics Specification](http://www.w3.org/TR/SVG/).
+ */
 library dart.dom.svg;
 
 import 'dart:async';