Revert "Change hover element to scrollbar's parent when hit test contains scrollbar"

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index baff1f456d551dd148bc6a6f4db1b2a2bbf54906..53d69df8b7bebd37217f1c7cac4ccafa9963ce8a 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -6049,22 +6049,14 @@ void Document::updateHoverActiveState(const HitTestRequest& request,
                                       Scrollbar* hitScrollbar) {
   DCHECK(!request.readOnly());
 
-  if (request.active() && m_frame)
-    m_frame->eventHandler().notifyElementActivated();
+  // Only cancel hover state when hitting native scrollbar because custom
+  // scrollbar's style depends on the owner element's hover state.
+  bool hitNativeScrollbar = hitScrollbar && !hitScrollbar->isCustomScrollbar();
 
-  Element* innerElementInDocument = hitScrollbar ? nullptr : innerElement;
-  // Replace the innerElementInDocument to be srollbar's parent when hit
-  // scrollbar
-  if (hitScrollbar) {
-    ScrollableArea* scrollableArea = hitScrollbar->getScrollableArea();
-    if (scrollableArea && scrollableArea->layoutBox() &&
-        scrollableArea->layoutBox()->node() &&
-        scrollableArea->layoutBox()->node()->isElementNode()) {
-      innerElementInDocument =
-          toElement(hitScrollbar->getScrollableArea()->layoutBox()->node());
-    }
-  }
+  if (request.active() && m_frame && !hitNativeScrollbar)
+    m_frame->eventHandler().notifyElementActivated();
 
+  Element* innerElementInDocument = hitNativeScrollbar ? nullptr : innerElement;
   while (innerElementInDocument && innerElementInDocument->document() != this) {
     innerElementInDocument->document().updateHoverActiveState(
         request, innerElementInDocument, hitScrollbar);
@@ -6073,7 +6065,7 @@ void Document::updateHoverActiveState(const HitTestRequest& request,
 
   updateDistribution();
   Element* oldActiveElement = activeHoverElement();
-  if (oldActiveElement && !request.active()) {
+  if (oldActiveElement && (!request.active() || hitNativeScrollbar)) {
     // The oldActiveElement layoutObject is null, dropped on :active by setting
     // display: none, for instance. We still need to clear the ActiveChain as
     // the mouse is released.