Subtree caching implementation in blink-core

Source/core/layout/LayoutPart.cpp

Index: Source/core/layout/LayoutPart.cpp
diff --git a/Source/core/layout/LayoutPart.cpp b/Source/core/layout/LayoutPart.cpp
index 7c06c2691ad27befcc59579db36081c3b927dc9b..1ea49e7b54577f4b3f4a4f3490c829d0522093a6 100644
--- a/Source/core/layout/LayoutPart.cpp
+++ b/Source/core/layout/LayoutPart.cpp
@@ -338,10 +338,16 @@ void LayoutPart::invalidatePaintOfSubtreesIfNeeded(PaintInvalidationState& paint
     if (widget() && widget()->isFrameView()) {
         FrameView* childFrameView = toFrameView(widget());
         PaintInvalidationState childViewPaintInvalidationState(*childFrameView->layoutView(), paintInvalidationState);
-        toFrameView(widget())->invalidateTreeIfNeeded(childViewPaintInvalidationState);
+        childFrameView->invalidateTreeIfNeeded(childViewPaintInvalidationState);
     }
 
     LayoutReplaced::invalidatePaintOfSubtreesIfNeeded(paintInvalidationState);
 }
 
+void LayoutPart::clearRepaintFlagsOfSubtrees()
+{
+    if (widget() && widget()->isFrameView())
+        toFrameView(widget())->layoutView()->clearRepaintFlagsRecursively();
+}
+
 }