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..e6dfab625ae01aa8b05b4a87f1eef3dc2ab6bcbc 100644
--- a/extensions/renderer/gc_callback_unittest.cc
+++ b/extensions/renderer/gc_callback_unittest.cc
@@ -14,6 +14,7 @@
 #include "extensions/renderer/scoped_web_frame.h"
 #include "extensions/renderer/script_context.h"
 #include "extensions/renderer/script_context_set.h"
+#include "extensions/renderer/test_extensions_renderer_client.h"
 #include "gin/function_template.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/web/WebFrame.h"
@@ -42,11 +43,10 @@ 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() {
@@ -73,6 +73,8 @@ class GCCallbackTest : public testing::Test {
 
   base::MessageLoop message_loop_;
   ScopedWebFrame web_frame_;  // (this will construct the v8::Isolate)
+  // ExtensionsRendererClient is a dependency of ScriptContextSet.
+  TestExtensionsRendererClient extensions_renderer_client_;
   ExtensionIdSet active_extensions_;
   ScriptContextSet script_context_set_;
   v8::Global<v8::Context> v8_context_;