Add support for surrogates when serializing and deserializing for native ports

runtime/vm/unicode.h

Index: runtime/vm/unicode.h
diff --git a/runtime/vm/unicode.h b/runtime/vm/unicode.h
index 03a4b29d879898c2c83f06aac4a175d4729db209..5c09b2ef0d6a4217aa62f0f5d7f108e45b9b5fb3 100644
--- a/runtime/vm/unicode.h
+++ b/runtime/vm/unicode.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
@@ -32,6 +32,11 @@ class Utf8 : AllStatic {
   // Returns true if 'utf8_array' is a valid UTF-8 string.
   static bool IsValid(const uint8_t* utf8_array, intptr_t array_len);
 
+  // Returns true if 'utf8_array' is a valid UTF-8 string allowing
+  // UTF-8 encoded UTF-16 surrogate code units.
+  static bool IsValidAllowSurrogates(
+      const uint8_t* utf8_array, intptr_t array_len);
+
   static intptr_t Length(int32_t ch);
   static intptr_t Length(const String& str);
 
@@ -41,6 +46,9 @@ class Utf8 : AllStatic {
   static intptr_t Decode(const uint8_t* utf8_array,
                          intptr_t array_len,
                          int32_t* ch);
+  static intptr_t DecodeAllowSurrogates(const uint8_t* utf8_array,
+                                        intptr_t array_len,
+                                        int32_t* ch);
 
   static bool DecodeToLatin1(const uint8_t* utf8_array,
                              intptr_t array_len,
@@ -50,6 +58,10 @@ class Utf8 : AllStatic {
                             intptr_t array_len,
                             uint16_t* dst,
                             intptr_t len);
+  static bool DecodeToUTF16AllowSurrogates(const uint8_t* utf8_array,
+                                           intptr_t array_len,
+                                           uint16_t* dst,
+                                           intptr_t len);
   static bool DecodeToUTF32(const uint8_t* utf8_array,
                             intptr_t array_len,
                             int32_t* dst,