binding: Changes the association among global-proxy/global/window-instance (2nd attempt).

third_party/WebKit/Source/bindings/core/v8/DOMDataStore.h

Index: third_party/WebKit/Source/bindings/core/v8/DOMDataStore.h
diff --git a/third_party/WebKit/Source/bindings/core/v8/DOMDataStore.h b/third_party/WebKit/Source/bindings/core/v8/DOMDataStore.h
index da4e201c9bb4ae4440cbee1c460c1719f5ee3899..a1a32f125f72deb6dcd3d098f53f11469c7c0b75 100644
--- a/third_party/WebKit/Source/bindings/core/v8/DOMDataStore.h
+++ b/third_party/WebKit/Source/bindings/core/v8/DOMDataStore.h
@@ -136,6 +136,12 @@ class DOMDataStore {
     wrapper_map_->MarkWrapper(script_wrappable);
   }
 
+  // Dissociates a wrapper, if any, from |script_wrappable|.
+  void UnsetWrapperIfAny(ScriptWrappable* script_wrappable) {
+    DCHECK(!is_main_world_);
+    wrapper_map_->RemoveIfAny(script_wrappable);
+  }
+
   bool SetReturnValueFrom(v8::ReturnValue<v8::Value> return_value,
                           ScriptWrappable* object) {
     if (is_main_world_)