Remove extension group from DOMWrapperWorld.

extensions/renderer/gc_callback_unittest.cc

Index: extensions/renderer/gc_callback_unittest.cc
diff --git a/extensions/renderer/gc_callback_unittest.cc b/extensions/renderer/gc_callback_unittest.cc
index 36f96604ddbd2ede9b09cb4e063c580fd3e5246e..d4f7368f6f702b88f66146c76f8b3ac2984b60e8 100644
--- a/extensions/renderer/gc_callback_unittest.cc
+++ b/extensions/renderer/gc_callback_unittest.cc
@@ -42,11 +42,10 @@ class GCCallbackTest : public testing::Test {
   }
 
   ScriptContext* RegisterScriptContext() {
-    // No extension group or world ID.
+    // No world ID.
     return script_context_set_.Register(
         web_frame_.frame(),
-        v8::Local<v8::Context>::New(v8::Isolate::GetCurrent(), v8_context_), 0,
-        0);
+        v8::Local<v8::Context>::New(v8::Isolate::GetCurrent(), v8_context_), 0);
   }
 
   void RequestGarbageCollection() {