Reland: Reland: Implement new Blink IDL attribute [SetReference]

Source/bindings/v8/WrapperTypeInfo.h

Index: Source/bindings/v8/WrapperTypeInfo.h
diff --git a/Source/bindings/v8/WrapperTypeInfo.h b/Source/bindings/v8/WrapperTypeInfo.h
index 9b7a3aa2b0ab8adc37ef9b1ad264df20eeab8825..97d1dd0460aff093b85fe35ab35fea5a4817dd65 100644
--- a/Source/bindings/v8/WrapperTypeInfo.h
+++ b/Source/bindings/v8/WrapperTypeInfo.h
@@ -60,7 +60,7 @@ namespace WebCore {
     typedef void (*DerefObjectFunction)(void*);
     typedef ActiveDOMObject* (*ToActiveDOMObjectFunction)(v8::Handle<v8::Object>);
     typedef EventTarget* (*ToEventTargetFunction)(v8::Handle<v8::Object>);
-    typedef void* (*OpaqueRootForGC)(void*, v8::Isolate*);
+    typedef void (*ResolveWrapperReachabilityFunction)(void*, const v8::Persistent<v8::Object>&, v8::Isolate*);
     typedef void (*InstallPerContextEnabledPrototypePropertiesFunction)(v8::Handle<v8::Object>, v8::Isolate*);
 
     enum WrapperTypePrototype {
@@ -68,6 +68,11 @@ namespace WebCore {
         WrapperTypeErrorPrototype
     };
 
+    inline void setObjectGroup(void* object, const v8::Persistent<v8::Object>& wrapper, v8::Isolate* isolate)
+    {
+        isolate->SetObjectGroupId(wrapper, v8::UniqueId(reinterpret_cast<intptr_t>(object)));
+    }
+
     // This struct provides a way to store a bunch of information that is helpful when unwrapping
     // v8 objects. Each v8 bindings class has exactly one static WrapperTypeInfo member, so
     // comparing pointers is a safe way to determine if types match.
@@ -122,18 +127,19 @@ namespace WebCore {
             return toEventTargetFunction(object);
         }
 
-        void* opaqueRootForGC(void* object, v8::Isolate* isolate) const
+        void resolveWrapperReachability(void* object, const v8::Persistent<v8::Object>& wrapper, v8::Isolate* isolate) const
         {
-            if (!opaqueRootForGCFunction)
-                return object;
-            return opaqueRootForGCFunction(object, isolate);
+            if (!resolveWrapperReachabilityFunction)
+                setObjectGroup(object, wrapper, isolate);
+            else
+                resolveWrapperReachabilityFunction(object, wrapper, isolate);
         }
 
         const GetTemplateFunction getTemplateFunction;
         const DerefObjectFunction derefObjectFunction;
         const ToActiveDOMObjectFunction toActiveDOMObjectFunction;
         const ToEventTargetFunction toEventTargetFunction;
-        const OpaqueRootForGC opaqueRootForGCFunction;
+        const ResolveWrapperReachabilityFunction resolveWrapperReachabilityFunction;
         const InstallPerContextEnabledPrototypePropertiesFunction installPerContextEnabledPrototypePropertiesFunction;
         const WrapperTypeInfo* parentClass;
         const WrapperTypePrototype wrapperTypePrototype;