Early-out from the prepaint tree walk

third_party/WebKit/Source/core/paint/FindPropertiesNeedingUpdate.h

Index: third_party/WebKit/Source/core/paint/FindPropertiesNeedingUpdate.h
diff --git a/third_party/WebKit/Source/core/paint/FindPropertiesNeedingUpdate.h b/third_party/WebKit/Source/core/paint/FindPropertiesNeedingUpdate.h
index fb3358b3aa74a4532ceb25d031c6e892b3e722f8..827c92de388f628589ca27bbc20ea09bd7b150ab 100644
--- a/third_party/WebKit/Source/core/paint/FindPropertiesNeedingUpdate.h
+++ b/third_party/WebKit/Source/core/paint/FindPropertiesNeedingUpdate.h
@@ -22,9 +22,13 @@ namespace blink {
 
 class FindFrameViewPropertiesNeedingUpdateScope {
  public:
-  FindFrameViewPropertiesNeedingUpdateScope(FrameView* frameView)
+  FindFrameViewPropertiesNeedingUpdateScope(
+      FrameView* frameView,
+      PaintPropertyTreeBuilderContext& context)
       : m_frameView(frameView),
-        m_neededPaintPropertyUpdate(frameView->needsPaintPropertyUpdate()) {
+        m_neededPaintPropertyUpdate(frameView->needsPaintPropertyUpdate()),
+        m_context(context),
+        m_hadForceSubtreeUpdate(context.forceSubtreeUpdate) {
     // No need to check when already marked as needing an update.
     if (m_neededPaintPropertyUpdate)
       return;
@@ -52,13 +56,16 @@ class FindFrameViewPropertiesNeedingUpdateScope {
     DCHECK_PTR_VAL_EQ(m_contentClip, m_frameView->contentClip());
     DCHECK_PTR_VAL_EQ(m_scrollTranslation, m_frameView->scrollTranslation());
     DCHECK_PTR_VAL_EQ(m_scroll, m_frameView->scroll());
-    // Restore original clean bit.
+    // Restore original clean bits.
     m_frameView->clearNeedsPaintPropertyUpdate();
+    m_context.forceSubtreeUpdate = m_hadForceSubtreeUpdate;
   }
 
  private:
   Persistent<FrameView> m_frameView;
   bool m_neededPaintPropertyUpdate;
+  PaintPropertyTreeBuilderContext& m_context;
+  bool m_hadForceSubtreeUpdate;
   RefPtr<TransformPaintPropertyNode> m_preTranslation;
   RefPtr<ClipPaintPropertyNode> m_contentClip;
   RefPtr<TransformPaintPropertyNode> m_scrollTranslation;
@@ -67,9 +74,13 @@ class FindFrameViewPropertiesNeedingUpdateScope {
 
 class FindObjectPropertiesNeedingUpdateScope {
  public:
-  FindObjectPropertiesNeedingUpdateScope(const LayoutObject& object)
+  FindObjectPropertiesNeedingUpdateScope(
+      const LayoutObject& object,
+      PaintPropertyTreeBuilderContext& context)
       : m_object(object),
-        m_neededPaintPropertyUpdate(object.needsPaintPropertyUpdate()) {
+        m_neededPaintPropertyUpdate(object.needsPaintPropertyUpdate()),
+        m_context(context),
+        m_hadForceSubtreeUpdate(context.forceSubtreeUpdate) {
     // No need to check when already marked as needing an update.
     if (m_neededPaintPropertyUpdate)
       return;
@@ -128,13 +139,16 @@ class FindObjectPropertiesNeedingUpdateScope {
     } else {
       DCHECK_EQ(!!m_properties, !!objectProperties);
     }
-    // Restore original clean bit.
+    // Restore original clean bits.
     const_cast<LayoutObject&>(m_object).clearNeedsPaintPropertyUpdate();
+    m_context.forceSubtreeUpdate = m_hadForceSubtreeUpdate;
   }
 
  private:
   const LayoutObject& m_object;
   bool m_neededPaintPropertyUpdate;
+  PaintPropertyTreeBuilderContext& m_context;
+  bool m_hadForceSubtreeUpdate;
   std::unique_ptr<const ObjectPaintProperties> m_properties;
 };