fix for 49835, r=danm

content/xbl/src/nsXBLService.cpp

@@ -354,6 +354,17 @@ nsXBLStreamListener::Load(nsIDOMEvent* aEvent)
       nsXBLBindingRequest* req = (nsXBLBindingRequest*)mBindingRequests.ElementAt(i);
       req->DocumentLoaded(mBindingDocument);
     }
+
+    // All reqs normally have the same binding doc.  Force a synchronous
+    // reflow on this binding doc to deal with the fact that iframes
+    // don't construct or load their subdocs until they get a reflow.
+    if (count > 0) {
+      nsXBLBindingRequest* req = (nsXBLBindingRequest*)mBindingRequests.ElementAt(i);
+      nsCOMPtr<nsIDocument> document;
+      req->mBoundElement->GetDocument(*getter_AddRefs(document));
+      if (document)
+        document->FlushPendingNotifications();
+    }
   }
   
   for (i = 0; i < count; i++) {

content/xul/document/src/nsXULDocument.cpp

@@ -4185,6 +4185,9 @@ nsXULDocument::StartLayout(void)
       }
 
       shell->InitialReflow(r.width, r.height);
+      FlushPendingNotifications(); // This is done because iframes don't load their subdocs until
+                                   // they get reflowed.  If we reflow asynchronously, our onload 
+                                   // will fire too early. -- hyatt
 
       // Start observing the document _after_ we do the initial
       // reflow. Otherwise, we'll get into an trouble trying to

layout/xbl/src/nsXBLService.cpp

@@ -354,6 +354,17 @@ nsXBLStreamListener::Load(nsIDOMEvent* aEvent)
       nsXBLBindingRequest* req = (nsXBLBindingRequest*)mBindingRequests.ElementAt(i);
       req->DocumentLoaded(mBindingDocument);
     }
+
+    // All reqs normally have the same binding doc.  Force a synchronous
+    // reflow on this binding doc to deal with the fact that iframes
+    // don't construct or load their subdocs until they get a reflow.
+    if (count > 0) {
+      nsXBLBindingRequest* req = (nsXBLBindingRequest*)mBindingRequests.ElementAt(i);
+      nsCOMPtr<nsIDocument> document;
+      req->mBoundElement->GetDocument(*getter_AddRefs(document));
+      if (document)
+        document->FlushPendingNotifications();
+    }
   }
   
   for (i = 0; i < count; i++) {

rdf/content/src/nsXULDocument.cpp

@@ -4185,6 +4185,9 @@ nsXULDocument::StartLayout(void)
       }
 
       shell->InitialReflow(r.width, r.height);
+      FlushPendingNotifications(); // This is done because iframes don't load their subdocs until
+                                   // they get reflowed.  If we reflow asynchronously, our onload 
+                                   // will fire too early. -- hyatt
 
       // Start observing the document _after_ we do the initial
       // reflow. Otherwise, we'll get into an trouble trying to