Added support for isolate unhandled exceptions.

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index aed8a1086d1bd174d31ee1f1a2c85e37ea6c6135..6e4f7ef1e331b56efe3bd7c15f49f2572f50070e 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -736,10 +736,12 @@ DART_EXPORT const char* Dart_VersionString() {
   return Version::String();
 }
 
-DART_EXPORT bool Dart_Initialize(Dart_IsolateCreateCallback create,
-                                 Dart_IsolateInterruptCallback interrupt,
-                                 Dart_IsolateShutdownCallback shutdown) {
-  const char* err_msg = Dart::InitOnce(create, interrupt, shutdown);
+DART_EXPORT bool Dart_Initialize(
+    Dart_IsolateCreateCallback create,
+    Dart_IsolateInterruptCallback interrupt,
+    Dart_IsolateUnhandledExceptionCallback unhandled,
+    Dart_IsolateShutdownCallback shutdown) {
+  const char* err_msg = Dart::InitOnce(create, interrupt, unhandled, shutdown);
   if (err_msg != NULL) {
     OS::PrintErr("Dart_Initialize: %s\n", err_msg);
     return false;