bindings: Add empty checks for toV8()

Source/bindings/core/v8/Iterable.h

Index: Source/bindings/core/v8/Iterable.h
diff --git a/Source/bindings/core/v8/Iterable.h b/Source/bindings/core/v8/Iterable.h
index 43125b418db3b641bbe4eb1adcf768055dea30a5..75adecc53b3241c160a32d5db1e589711e3a0bba 100644
--- a/Source/bindings/core/v8/Iterable.h
+++ b/Source/bindings/core/v8/Iterable.h
@@ -64,6 +64,11 @@ public:
 
             args[0] = toV8(value, creationContext, isolate);
             args[1] = toV8(key, creationContext, isolate);
+            if (args[0].IsEmpty() || args[1].IsEmpty()) {
+                if (tryCatch.HasCaught())

[haraken, 2015/04/28 05:50:34]

Do we need the HasCaught check?

[bashi, 2015/04/28 06:41:14]

toV8() doesn't guarantee that there is an exception on failure. That's a reason
why I didn't change return type of toV8() to MaybeLocal.

+                    exceptionState.rethrowV8Exception(tryCatch.Exception());
+                return;
+            }
 
             v8::Local<v8::Value> result;
             if (!V8ScriptRunner::callFunction(v8Callback, scriptState->executionContext(), v8ThisArg, 3, args, isolate).ToLocal(&result)) {