Throw exception on invalid string length instead of OOM.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index d0c9d26a04ad74d2ddd12b8b04a6c775985a95d2..ddcc682e2f33f75adf3263f7894bd7d226181a70 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -5475,6 +5475,8 @@ Local<String> v8::String::Concat(Handle<String> left, Handle<String> right) {
   i::Handle<i::String> right_string = Utils::OpenHandle(*right);
   i::Handle<i::String> result = isolate->factory()->NewConsString(left_string,
                                                                   right_string);
+  // We do not expect this to throw an exception. Change this if it does.
+  CHECK_NOT_EMPTY_HANDLE(isolate, result);
   return Utils::ToLocal(result);
 }
 
@@ -6966,9 +6968,12 @@ Handle<String> CpuProfileNode::GetFunctionName() const {
     return ToApiHandle<String>(
         isolate->factory()->InternalizeUtf8String(entry->name()));
   } else {
-    return ToApiHandle<String>(isolate->factory()->NewConsString(
+    i::Handle<i::String> cons = isolate->factory()->NewConsString(
         isolate->factory()->InternalizeUtf8String(entry->name_prefix()),
-        isolate->factory()->InternalizeUtf8String(entry->name())));
+        isolate->factory()->InternalizeUtf8String(entry->name()));
+    // We do not expect this to throw an exception. Change this if it does.
+    CHECK_NOT_EMPTY_HANDLE(isolate, cons);
+    return ToApiHandle<String>(cons);
   }
 }