bindings: Removes two FIXMEs because setReturnValueFast is useful.

Source/bindings/core/v8/DOMDataStore.h

Index: Source/bindings/core/v8/DOMDataStore.h
diff --git a/Source/bindings/core/v8/DOMDataStore.h b/Source/bindings/core/v8/DOMDataStore.h
index 2d6d11b0e504c685502673e8e34a4f70f4a6678f..7ab5ae8a5c8c20c0a3eedb692b982d9cb9176894 100644
--- a/Source/bindings/core/v8/DOMDataStore.h
+++ b/Source/bindings/core/v8/DOMDataStore.h
@@ -65,7 +65,6 @@ public:
     {
         // The second fastest way to check if we're in the main world is to check if
         // the wrappable's wrapper is the same as the holder.
-        // FIXME: Investigate if it's worth having this check for performance.
         if (holderContainsWrapper(holder, wrappable))
             return object->setReturnValue(returnValue);
         return current(returnValue.GetIsolate()).setReturnValueFrom(returnValue, object);
@@ -76,7 +75,6 @@ public:
         if (canUseScriptWrappable(node)
             // The second fastest way to check if we're in the main world is to
             // check if the wrappable's wrapper is the same as the holder.
-            // FIXME: Investigate if it's worth having this check for performance.
             || holderContainsWrapper(holder, wrappable))
             return ScriptWrappable::fromNode(node)->setReturnValue(returnValue);
         return current(returnValue.GetIsolate()).setReturnValueFrom(returnValue, ScriptWrappable::fromNode(node));