--- a/layout/base/nsCSSFrameConstructor.cpp
+++ b/layout/base/nsCSSFrameConstructor.cpp
@@ -2514,23 +2514,30 @@ nsCSSFrameConstructor::ConstructDocEleme
   // the future.  We need this, because the document element might
   // have stale restyle bits from a previous frame constructor for
   // this document.  Unlike in AddFrameConstructionItems, it's safe to
   // unset all element restyle flags, since we don't have any
   // siblings.
   aDocElement->UnsetRestyleFlagsIfGecko();
 
   // --------- CREATE AREA OR BOX FRAME -------
+  if (ServoStyleSet* set = mPresShell->StyleSet()->GetAsServo()) {
+    // NOTE(emilio): If the root has a non-null binding, we'll stop at the
+    // document element and won't process any children, loading the bindings (or
+    // failing to do so) will take care of the rest.
+    set->StyleDocument(TraversalRestyleBehavior::Normal);
+  }
+
   // FIXME: Should this use ResolveStyleContext?  (The calls in this
   // function are the only case in nsCSSFrameConstructor where we don't
   // do so for the construction of a style context for an element.)
-  RefPtr<nsStyleContext> styleContext;
-  styleContext = mPresShell->StyleSet()->ResolveStyleFor(aDocElement,
-                                                         nullptr,
-                                                         LazyComputeBehavior::Allow);
+  RefPtr<nsStyleContext> styleContext =
+    mPresShell->StyleSet()->ResolveStyleFor(aDocElement,
+                                            nullptr,
+                                            LazyComputeBehavior::Assert);
 
   const nsStyleDisplay* display = styleContext->StyleDisplay();
 
   // Ensure that our XBL bindings are installed.
   if (display->mBinding) {
     // Get the XBL loader.
     nsresult rv;
     bool resolveStyle;
@@ -2539,42 +2546,48 @@ nsCSSFrameConstructor::ConstructDocEleme
     if (!xblService) {
       return nullptr;
     }
 
     RefPtr<nsXBLBinding> binding;
     rv = xblService->LoadBindings(aDocElement, display->mBinding->GetURI(),
                                   display->mBinding->mExtraData->GetPrincipal(),
                                   getter_AddRefs(binding), &resolveStyle);
-    if (NS_FAILED(rv) && rv != NS_ERROR_XBL_BLOCKED)
-      return nullptr; // Binding will load asynchronously.
+    if (NS_FAILED(rv) && rv != NS_ERROR_XBL_BLOCKED) {
+      // Binding will load asynchronously.
+      if (aDocElement->IsStyledByServo()) {
+        ServoRestyleManager::ClearServoDataFromSubtree(aDocElement);
+      }
+      return nullptr;
+    }
 
     if (binding) {
       // For backwards compat, keep firing the root's constructor
       // after all of its kids' constructors.  So tell the binding
       // manager about it right now.
       mDocument->BindingManager()->AddToAttachedQueue(binding);
     }
 
     if (resolveStyle) {
       // FIXME: Should this use ResolveStyleContext?  (The calls in this
       // function are the only case in nsCSSFrameConstructor where we
       // don't do so for the construction of a style context for an
       // element.)
-      styleContext = mPresShell->StyleSet()->ResolveStyleFor(aDocElement,
-                                                             nullptr,
-                                                             LazyComputeBehavior::Allow);
+      //
+      // FIXME(emilio): This looks fishy. It really wants to fully re-resolve
+      // the style, but it wont if the element is already styled afaict... It
+      // seems we handle it on a subsequent restyle?
+      styleContext = mPresShell->StyleSet()->ResolveStyleFor(
+          aDocElement, nullptr, LazyComputeBehavior::Assert);
       display = styleContext->StyleDisplay();
     }
-  }
-
-  // We delay traversing the entire document until here, since we per above we
-  // may invalidate the root style when we load doc stylesheets.
-  if (ServoStyleSet* set = mPresShell->StyleSet()->GetAsServo()) {
-    set->StyleDocument(TraversalRestyleBehavior::Normal);
+  } else if (display->mBinding.ForceGet() && aDocElement->IsStyledByServo()) {
+    // See the comment in AddFrameConstructionItemsInternal for why this is
+    // needed.
+    mPresShell->StyleSet()->AsServo()->StyleNewChildren(aDocElement);
   }
 
   // --------- IF SCROLLABLE WRAP IN SCROLLFRAME --------
 
   NS_ASSERTION(!display->IsScrollableOverflow() ||
                state.mPresContext->IsPaginated() ||
                propagatedScrollFrom == aDocElement,
                "Scrollbars should have been propagated to the viewport");
@@ -5868,19 +5881,18 @@ nsCSSFrameConstructor::AddFrameConstruct
           // XXX: We should have a better way to restyle ourselves.
           ServoRestyleManager::ClearServoDataFromSubtree(element);
           styleSet->StyleNewSubtree(element);
 
           // Servo's should_traverse_children() in traversal.rs skips
           // styling descendants of elements with a -moz-binding the
           // first time. Thus call StyleNewChildren() again.
           styleSet->StyleNewChildren(element);
-
           styleContext =
-            styleSet->ResolveStyleFor(element, nullptr, LazyComputeBehavior::Allow);
+            styleSet->ResolveStyleFor(element, nullptr, LazyComputeBehavior::Assert);
         } else {
           styleContext =
             ResolveStyleContext(styleContext->GetParent(), aContent, &aState);
         }
 
         display = styleContext->StyleDisplay();
         aStyleContext = styleContext;
       }

--- a/layout/base/nsPresContext.cpp
+++ b/layout/base/nsPresContext.cpp
@@ -1480,19 +1480,18 @@ GetPropagatedScrollbarStylesForViewport(
 
   // docElement might be null if we're doing this after removing it.
   if (!docElement) {
     return nullptr;
   }
 
   // Check the style on the document root element
   StyleSetHandle styleSet = aPresContext->StyleSet();
-  RefPtr<nsStyleContext> rootStyle;
-  rootStyle = styleSet->ResolveStyleFor(docElement, nullptr,
-                                        LazyComputeBehavior::Allow);
+  RefPtr<nsStyleContext> rootStyle =
+    styleSet->ResolveStyleFor(docElement, nullptr, LazyComputeBehavior::Allow);
   if (CheckOverflow(rootStyle->StyleDisplay(), aStyles)) {
     // tell caller we stole the overflow style from the root element
     return docElement;
   }
 
   // Don't look in the BODY for non-HTML documents or HTML documents
   // with non-HTML roots
   // XXX this should be earlier; we shouldn't even look at the document root
@@ -1509,19 +1508,19 @@ GetPropagatedScrollbarStylesForViewport(
   nsCOMPtr<nsIContent> bodyElement = do_QueryInterface(body);
 
   if (!bodyElement ||
       !bodyElement->NodeInfo()->Equals(nsGkAtoms::body)) {
     // The body is not a <body> tag, it's a <frameset>.
     return nullptr;
   }
 
-  RefPtr<nsStyleContext> bodyStyle;
-  bodyStyle = styleSet->ResolveStyleFor(bodyElement->AsElement(), rootStyle,
-                                        LazyComputeBehavior::Allow);
+  RefPtr<nsStyleContext> bodyStyle =
+    styleSet->ResolveStyleFor(bodyElement->AsElement(), rootStyle,
+                              LazyComputeBehavior::Allow);
 
   if (CheckOverflow(bodyStyle->StyleDisplay(), aStyles)) {
     // tell caller we stole the overflow style from the body element
     return bodyElement;
   }
 
   return nullptr;
 }