dart:io | Add SecureSocket.importPrivateCertificates, that reads a PKCS#12 file.

sdk/lib/_internal/lib/io_patch.dart

Index: sdk/lib/_internal/lib/io_patch.dart
diff --git a/sdk/lib/_internal/lib/io_patch.dart b/sdk/lib/_internal/lib/io_patch.dart
index d5e55c66b05ad64cf0bbf99a974185c8a932a85c..b40c003b9a6f2d7794bbcf757e7d22c1e4d5b68e 100644
--- a/sdk/lib/_internal/lib/io_patch.dart
+++ b/sdk/lib/_internal/lib/io_patch.dart
@@ -274,7 +274,8 @@ patch class SecureSocket {
 
   patch static void initialize({String database,
                                 String password,
-                                bool useBuiltinRoots: true}) {
+                                bool useBuiltinRoots: true,
+                                bool readOnly: true}) {
     throw new UnsupportedError("SecureSocket.initialize");
   }
 
@@ -282,6 +283,20 @@ patch class SecureSocket {
                                               String trust) {
     throw new UnsupportedError("SecureSocket.addCertificate");
   }
+
+  patch static importPrivateCertificates(List<int> certificates,
+                                         String password) {
+    throw new UnsupportedError("SecureSocket.importPrivateCertificates");
+  }
+
+  patch static removeCertificate(String nicknameOrDN) {
+    throw new UnsupportedError("SecureSocket.removeCertificate");
+  }
+
+  patch static X509Certificate changeTrust(String nicknameOrDN,
+                                           String trust) {
+    throw new UnsupportedError("SecureSocket.changeTrust");
+  }
 }
 
 patch class _SecureFilter {