Added API Dart_PostCMessage for posting a Dart_CMessage structure

runtime/vm/dart_api_impl_test.cc

Index: runtime/vm/dart_api_impl_test.cc
diff --git a/runtime/vm/dart_api_impl_test.cc b/runtime/vm/dart_api_impl_test.cc
index f42dd48a262123cf02a5be09a50a451f1bc63989..5c40fdceca945201d6f34b6568aedb370123c9da 100644
--- a/runtime/vm/dart_api_impl_test.cc
+++ b/runtime/vm/dart_api_impl_test.cc
@@ -2828,16 +2828,26 @@ TEST_CASE(ImportLibrary5) {
 void NewNativePort_send123(Dart_Port dest_port_id,
                            Dart_Port reply_port_id,
                            uint8_t* data) {
-  intptr_t response = 123;
-  Dart_PostIntArray(reply_port_id, 1, &response);
+  // Post integer value.
+  Dart_CObject object;
+  object.type = Dart_CObject::kInt32;
+  object.value.as_int32 = 123;
+  Dart_CMessage message;
+  message.root = &object;
+  Dart_PostCMessage(reply_port_id, &message);
 }
 
 
 void NewNativePort_send321(Dart_Port dest_port_id,
                            Dart_Port reply_port_id,
                            uint8_t* data) {
-  intptr_t response = 321;
-  Dart_PostIntArray(reply_port_id, 1, &response);
+  // Post integer value.
+  Dart_CObject object;
+  object.type = Dart_CObject::kInt32;
+  object.value.as_int32 = 321;
+  Dart_CMessage message;
+  message.root = &object;
+  Dart_PostCMessage(reply_port_id, &message);
 }
 
 
@@ -2854,7 +2864,7 @@ UNIT_TEST_CASE(NewNativePort) {
   const char* kScriptChars =
       "void callPort(SendPort port) {\n"
       "    port.call(null).receive((message, replyTo) {\n"
-      "      throw new Exception(message[0]);\n"
+      "      throw new Exception(message);\n"
       "    });\n"
       "}\n";
   Dart_Handle lib = TestCase::LoadTestScript(kScriptChars, NULL);