Use shelf's Server API in browser/server.

lib/src/util/io.dart

Index: lib/src/util/io.dart
diff --git a/lib/src/util/io.dart b/lib/src/util/io.dart
index ceb8da6c9992ecc06e79cb933e99eab5d0b4805a..8ae80b5f542a466ffa071599f33ac170d515ae12 100644
--- a/lib/src/util/io.dart
+++ b/lib/src/util/io.dart
@@ -126,23 +126,6 @@ void warn(String message, {bool color}) {
   stderr.writeln(wordWrap("$header $message\n"));
 }
 
-/// Creates a URL string for [address]:[port].
-///
-/// Handles properly formatting IPv6 addresses.
-Uri baseUrlForAddress(InternetAddress address, int port) {
-  if (address.isLoopback) {
-    return new Uri(scheme: "http", host: "localhost", port: port);
-  }
-
-  // IPv6 addresses in URLs need to be enclosed in square brackets to avoid
-  // URL ambiguity with the ":" in the address.
-  if (address.type == InternetAddressType.IP_V6) {
-    return new Uri(scheme: "http", host: "[${address.address}]", port: port);
-  }
-
-  return new Uri(scheme: "http", host: address.address, port: port);
-}
-
 /// Returns the package root at [root].
 ///
 /// If [override] is passed, that's used. If the package root doesn't exist, an