Bug 1392863 - Clean up DoProcessPendingRestyles. r=emilio

MozReview-Commit-ID: 4JhWFNPVvGn

layout/base/ServoRestyleManager.cpp

@@ -1012,16 +1012,7 @@ ServoRestyleManager::DoProcessPendingRestyles(ServoTraversalFlags aFlags)
     aFlags |= ServoTraversalFlags::ForCSSRuleChanges;
   }
 
-  while (doc->GetServoRestyleRoot()) {
-    // Do the servo traversal.
-    bool needsPostTraversal = styleSet->StyleDocument(aFlags);
-
-    // If we don't need a post-traversal, we're done.
-    if (!needsPostTraversal) {
-      doc->ClearServoRestyleRoot();
-      break;
-    }
-
+  while (styleSet->StyleDocument(aFlags)) {
     ClearSnapshots();
 
     nsStyleChangeList currentChanges(StyleBackendType::Servo);
@@ -1086,6 +1077,8 @@ ServoRestyleManager::DoProcessPendingRestyles(ServoTraversalFlags aFlags)
     }
   }
 
+  doc->ClearServoRestyleRoot();
+
   FlushOverflowChangedTracker();
 
   ClearSnapshots();

layout/style/ServoStyleSet.cpp

@@ -858,6 +858,11 @@ ServoStyleSet::HasStateDependentStyle(dom::Element* aElement,
 bool
 ServoStyleSet::StyleDocument(ServoTraversalFlags aBaseFlags)
 {
+  nsIDocument* doc = mPresContext->Document();
+  if (!doc->GetServoRestyleRoot()) {
+    return false;
+  }
+
   PreTraverse(aBaseFlags);
   AutoPrepareTraversal guard(this);
   const SnapshotTable& snapshots = Snapshots();
@@ -866,7 +871,6 @@ ServoStyleSet::StyleDocument(ServoTraversalFlags aBaseFlags)
   // NAC subtree roots.
   bool postTraversalRequired = false;
 
-  nsIDocument* doc = mPresContext->Document();
   Element* rootElement = doc->GetRootElement();
   // NB: We distinguish between the main document and document-level NAC here.
   const bool isInitialForMainDoc = rootElement && !rootElement->HasServoData();