Fix detached event listener attribute updating.

third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp

Index: third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp b/third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp
index f37c4371737d9f5b7e06eff8289acb743fc36895..45fa39bd1a223062c8bb5feb21fc313d750e3a2c 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp
@@ -198,16 +198,15 @@ v8::Local<v8::Object> V8AbstractEventListener::GetReceiverObject(
 }
 
 bool V8AbstractEventListener::BelongsToTheCurrentWorld(
-    ExecutionContext* execution_context) const {
+    Document* document) const {
   if (!GetIsolate()->GetCurrentContext().IsEmpty() &&
       &World() == &DOMWrapperWorld::Current(GetIsolate()))
     return true;
   // If currently parsing, the parser could be accessing this listener
   // outside of any v8 context; check if it belongs to the main world.
-  if (!GetIsolate()->InContext() && execution_context->IsDocument()) {
-    Document* document = ToDocument(execution_context);
-    if (document->Parser() && document->Parser()->IsParsing())
-      return World().IsMainWorld();
+  if (!GetIsolate()->InContext() && document && document->Parser() &&
+      document->Parser()->IsParsing()) {
+    return World().IsMainWorld();
   }
   return false;
 }