Expand PaintLayer clip to account for hidden URL bar with document.rootScroller

third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp

Index: third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
diff --git a/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp b/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
index 270b7c55e2408516c9bd21a83341f8c5482ecfc3..6121600b8f3157dff3850815c54fd395d057bb71 100644
--- a/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
+++ b/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
@@ -66,9 +66,10 @@ ScrollableArea* TopDocumentRootScrollerController::rootScrollerArea() const {
   return RootScrollerUtil::scrollableAreaForRootScroller(globalRootScroller());
 }
 
-IntSize TopDocumentRootScrollerController::rootScrollerVisibleArea() const {
+IntRect TopDocumentRootScrollerController::visibleContentRect(
+    IncludeScrollbarsInRect includeScrollbars) const {
   if (!topDocument() || !topDocument()->view())
-    return IntSize();
+    return IntRect();
 
   float minimumPageScale =
       m_frameHost->pageScaleConstraintsSet().finalConstraints().minimumScale;
@@ -76,8 +77,28 @@ IntSize TopDocumentRootScrollerController::rootScrollerVisibleArea() const {
       ceilf(m_frameHost->visualViewport().browserControlsAdjustment() /
             minimumPageScale);
 
-  return topDocument()->view()->visibleContentSize(ExcludeScrollbars) +
-         IntSize(0, browserControlsAdjustment);
+  IntRect rect = topDocument()->view()->visibleContentRect(includeScrollbars);
+  rect.expand(0, browserControlsAdjustment);
+
+  return rect;
+}
+
+bool TopDocumentRootScrollerController::isRootScrollerAncestor(
+    const Node& node) const {
+  Node* curNode = globalRootScroller();
+
+  while (curNode) {
+    if (node.isSameNode(curNode))
+      return true;
+
+    // TODO(bokan): This won't work for OOPIF. crbug.com/642378.
+    if (curNode->isDocumentNode())
+      curNode = toDocument(curNode)->localOwner();
+    else
+      curNode = curNode->parentNode();
+  }
+
+  return false;
 }
 
 Element* TopDocumentRootScrollerController::findGlobalRootScrollerElement() {