Bug 1514251 part 2. Update naming in ReparentWrapper to reflect reality. r=peterv

We're not changing parents; we're changing globals.  Let's be clear about that.

dom/base/nsFrameLoader.cpp

@@ -1740,7 +1740,7 @@ void nsFrameLoader::SetOwnerContent(Element* aContent) {
   if (wrapper) {
     JSAutoRealm ar(jsapi.cx(), wrapper);
     IgnoredErrorResult rv;
-    ReparentWrapper(jsapi.cx(), wrapper, rv);
+    UpdateReflectorGlobal(jsapi.cx(), wrapper, rv);
     Unused << NS_WARN_IF(rv.Failed());
   }
 

dom/base/nsINode.cpp

@@ -1189,12 +1189,12 @@ static void CheckForOutdatedParent(nsINode* aParent, nsINode* aNode,
 
     if (JS::GetNonCCWObjectGlobal(existingObj) != global->GetGlobalJSObject()) {
       JSAutoRealm ar(cx, existingObj);
-      ReparentWrapper(cx, existingObj, aError);
+      UpdateReflectorGlobal(cx, existingObj, aError);
     }
   }
 }
 
-static nsresult ReparentWrappersInSubtree(nsIContent* aRoot) {
+static nsresult UpdateGlobalsInSubtree(nsIContent* aRoot) {
   MOZ_ASSERT(ShouldUseXBLScope(aRoot));
   // Start off with no global so we don't fire any error events on failure.
   AutoJSAPI jsapi;
@@ -1207,7 +1207,7 @@ static nsresult ReparentWrappersInSubtree(nsIContent* aRoot) {
   for (nsIContent* cur = aRoot; cur; cur = cur->GetNextNode(aRoot)) {
     if ((reflector = cur->GetWrapper())) {
       JSAutoRealm ar(cx, reflector);
-      ReparentWrapper(cx, reflector, rv);
+      UpdateReflectorGlobal(cx, reflector, rv);
       rv.WouldReportJSException();
       if (rv.Failed()) {
         // We _could_ consider BlastSubtreeToPieces here, but it's not really
@@ -1279,7 +1279,7 @@ nsresult nsINode::InsertChildBefore(nsIContent* aKid,
   if (NS_SUCCEEDED(rv) && !wasInXBLScope && ShouldUseXBLScope(aKid)) {
     MOZ_ASSERT(ShouldUseXBLScope(this),
                "Why does the kid need to use an XBL scope?");
-    rv = ReparentWrappersInSubtree(aKid);
+    rv = UpdateGlobalsInSubtree(aKid);
   }
   if (NS_FAILED(rv)) {
     DisconnectChild(aKid);

dom/base/nsNodeUtils.cpp

@@ -516,7 +516,7 @@ already_AddRefed<nsINode> nsNodeUtils::CloneAndAdopt(
       if ((wrapper = aNode->GetWrapper())) {
         MOZ_ASSERT(IsDOMObject(wrapper));
         JSAutoRealm ar(cx, wrapper);
-        ReparentWrapper(cx, wrapper, aError);
+        UpdateReflectorGlobal(cx, wrapper, aError);
         if (aError.Failed()) {
           if (wasRegistered) {
             aNode->OwnerDoc()->UnregisterActivityObserver(aNode->AsElement());

dom/bindings/BindingUtils.cpp

@@ -2123,8 +2123,8 @@ bool DictionaryBase::AppendJSONToString(const char16_t* aJSONData,
   return true;
 }
 
-void ReparentWrapper(JSContext* aCx, JS::Handle<JSObject*> aObjArg,
-                     ErrorResult& aError) {
+void UpdateReflectorGlobal(JSContext* aCx, JS::Handle<JSObject*> aObjArg,
+                           ErrorResult& aError) {
   js::AssertSameCompartment(aCx, aObjArg);
 
   aError.MightThrowJSException();
@@ -2139,19 +2139,20 @@ void ReparentWrapper(JSContext* aCx, JS::Handle<JSObject*> aObjArg,
   }
 
   JS::Rooted<JSObject*> aObj(aCx, aObjArg);
+  MOZ_ASSERT(IsDOMObject(aObj));
+
   const DOMJSClass* domClass = GetDOMClass(aObj);
 
-  // DOM things are always parented to globals.
-  JS::Rooted<JSObject*> oldParent(aCx, JS::GetNonCCWObjectGlobal(aObj));
-  MOZ_ASSERT(JS_IsGlobalObject(oldParent));
+  JS::Rooted<JSObject*> oldGlobal(aCx, JS::GetNonCCWObjectGlobal(aObj));
+  MOZ_ASSERT(JS_IsGlobalObject(oldGlobal));
 
-  JS::Rooted<JSObject*> newParent(aCx,
+  JS::Rooted<JSObject*> newGlobal(aCx,
                                   domClass->mGetAssociatedGlobal(aCx, aObj));
-  MOZ_ASSERT(JS_IsGlobalObject(newParent));
+  MOZ_ASSERT(JS_IsGlobalObject(newGlobal));
 
-  JSAutoRealm oldAr(aCx, oldParent);
+  JSAutoRealm oldAr(aCx, oldGlobal);
 
-  if (oldParent == newParent) {
+  if (oldGlobal == newGlobal) {
     return;
   }
 
@@ -2166,7 +2167,7 @@ void ReparentWrapper(JSContext* aCx, JS::Handle<JSObject*> aObjArg,
     expandoObject = DOMProxyHandler::GetAndClearExpandoObject(aObj);
   }
 
-  JSAutoRealm newAr(aCx, newParent);
+  JSAutoRealm newAr(aCx, newGlobal);
 
   // First we clone the reflector. We get a copy of its properties and clone its
   // expando chain.

dom/bindings/BindingUtils.h

@@ -2326,10 +2326,16 @@ const nsAString& NonNullHelper(const binding_detail::FakeString& aArg) {
   return aArg;
 }
 
-// Reparent the wrapper of aObj to whatever its native now thinks its
-// parent should be.
-void ReparentWrapper(JSContext* aCx, JS::Handle<JSObject*> aObj,
-                     ErrorResult& aError);
+// Given a DOM reflector aObj, give its underlying DOM object a reflector in
+// whatever global that underlying DOM object now thinks it should be in.  If
+// this is in a different compartment from aObj, aObj will become a
+// cross-compatment wrapper for the new object.  Otherwise, aObj will become the
+// new object (via a brain transplant).  If the new global is the same as the
+// old global, we just keep using the same object.
+//
+// On entry to this method, aCx and aObj must be same-compartment.
+void UpdateReflectorGlobal(JSContext* aCx, JS::Handle<JSObject*> aObj,
+                           ErrorResult& aError);
 
 /**
  * Used to implement the Symbol.hasInstance property of an interface object.

dom/html/nsHTMLDocument.cpp

@@ -1449,7 +1449,7 @@ already_AddRefed<nsIDocument> nsHTMLDocument::Open(
     JS::Rooted<JSObject*> wrapper(cx, GetWrapper());
     if (oldScope && newScope != oldScope && wrapper) {
       JSAutoRealm ar(cx, wrapper);
-      mozilla::dom::ReparentWrapper(cx, wrapper, aError);
+      UpdateReflectorGlobal(cx, wrapper, aError);
       if (aError.Failed()) {
         return nullptr;
       }
@@ -1460,7 +1460,7 @@ already_AddRefed<nsIDocument> nsHTMLDocument::Open(
         JS::Rooted<JSObject*> contentsOwnerWrapper(
             cx, mTemplateContentsOwner->GetWrapper());
         if (contentsOwnerWrapper) {
-          mozilla::dom::ReparentWrapper(cx, contentsOwnerWrapper, aError);
+          UpdateReflectorGlobal(cx, contentsOwnerWrapper, aError);
           if (aError.Failed()) {
             return nullptr;
           }