Added API Dart_PostCMessage for posting a Dart_CMessage structure

runtime/bin/eventhandler_linux.cc

Index: runtime/bin/eventhandler_linux.cc
diff --git a/runtime/bin/eventhandler_linux.cc b/runtime/bin/eventhandler_linux.cc
index c46c89c0b06259eecc40751791d81e4ea9d48242..fdd09911bbc425731a97425ea4e41137a69a351e 100644
--- a/runtime/bin/eventhandler_linux.cc
+++ b/runtime/bin/eventhandler_linux.cc
@@ -12,6 +12,7 @@
 #include <sys/time.h>
 #include <unistd.h>
 
+#include "bin/dartutils.h"
 #include "bin/fdutils.h"
 #include "bin/hashmap.h"
 #include "platform/utils.h"
@@ -311,7 +312,7 @@ void EventHandlerImplementation::HandleEvents(struct pollfd* pollfds,
         Dart_Port port = sd->port();
         ASSERT(port != 0);
         sd->Unregister();
-        Dart_PostIntArray(port, 1, &event_mask);
+        DartUtils::PostInt32(port, event_mask);
       }
     }
   }
@@ -332,7 +333,7 @@ void EventHandlerImplementation::HandleTimeout() {
   if (timeout_ != kInfinityTimeout) {
     intptr_t millis = timeout_ - GetCurrentTimeMilliseconds();
     if (millis <= 0) {
-      Dart_PostIntArray(timeout_port_, 0, NULL);
+      DartUtils::PostNull(timeout_port_);
       timeout_ = kInfinityTimeout;
       timeout_port_ = 0;
     }