Start using Dart_PropagateError in the runtime/bin directory.

runtime/bin/dartutils.cc

Index: runtime/bin/dartutils.cc
===================================================================
--- runtime/bin/dartutils.cc	(revision 5191)
+++ runtime/bin/dartutils.cc	(working copy)
@@ -47,7 +47,9 @@
   ASSERT(Dart_IsInteger(value_obj));
   int64_t value = 0;
   Dart_Handle result = Dart_IntegerToInt64(value_obj, &value);
-  ASSERT(!Dart_IsError(result));
+  if (Dart_IsError(result)) {
+    Dart_PropagateError(result);
+  }
   return value;
 }
 
@@ -55,7 +57,9 @@
 const char* DartUtils::GetStringValue(Dart_Handle str_obj) {
   const char* cstring = NULL;
   Dart_Handle result = Dart_StringToCString(str_obj, &cstring);
-  ASSERT(!Dart_IsError(result));
+  if (Dart_IsError(result)) {
+    Dart_PropagateError(result);
+  }
   return cstring;
 }
 
@@ -63,7 +67,9 @@
 bool DartUtils::GetBooleanValue(Dart_Handle bool_obj) {
   bool value = false;
   Dart_Handle result = Dart_BooleanValue(bool_obj, &value);
-  ASSERT(!Dart_IsError(result));
+  if (Dart_IsError(result)) {
+    Dart_PropagateError(result);
+  }
   return value;
 }
 
@@ -74,14 +80,18 @@
   Dart_Handle result = Dart_SetField(handle,
                                      Dart_NewString(name),
                                      Dart_NewInteger(val));
-  ASSERT(!Dart_IsError(result));
+  if (Dart_IsError(result)) {
+    Dart_PropagateError(result);
+  }
 }
 
 
 intptr_t DartUtils::GetIntegerField(Dart_Handle handle,
                                             const char* name) {
   Dart_Handle result = Dart_GetField(handle, Dart_NewString(name));
-  ASSERT(!Dart_IsError(result));
+  if (Dart_IsError(result)) {
+    Dart_PropagateError(result);
+  }
   intptr_t value = DartUtils::GetIntegerValue(result);
   return value;
 }
@@ -93,7 +103,9 @@
   Dart_Handle result = Dart_SetField(handle,
                                      Dart_NewString(name),
                                      Dart_NewString(val));
-  ASSERT(!Dart_IsError(result));
+  if (Dart_IsError(result)) {
+    Dart_PropagateError(result);
+  }
 }
 
 
@@ -140,7 +152,7 @@
   // Get the url of the including library.
   Dart_Handle library_url = Dart_LibraryUrl(library);
   if (Dart_IsError(library_url)) {
-    return Dart_Error("accessing library url failed");
+    return library_url;
   }
   if (!Dart_IsString8(library_url)) {
     return Dart_Error("library url is not a string");
@@ -148,7 +160,7 @@
   const char* library_url_str = NULL;
   Dart_Handle result = Dart_StringToCString(library_url, &library_url_str);
   if (Dart_IsError(result)) {
-    return Dart_Error("accessing library url characters failed");
+    return result;
   }
   if (url_mapping != NULL) {
     const char* mapped_library_url_str = MapLibraryUrl(url_mapping,