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

third_party/WebKit/Source/core/input/EventHandlingUtil.cpp

Index: third_party/WebKit/Source/core/input/EventHandlingUtil.cpp
diff --git a/third_party/WebKit/Source/core/input/EventHandlingUtil.cpp b/third_party/WebKit/Source/core/input/EventHandlingUtil.cpp
index 908de11084e01bf8a44b9de6c32cb8ae855d5339..0c3903dda6c6db44debbf5491cce2c707be99951 100644
--- a/third_party/WebKit/Source/core/input/EventHandlingUtil.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandlingUtil.cpp
@@ -4,9 +4,11 @@
 
 #include "core/input/EventHandlingUtil.h"
 
+#include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/layout/api/LayoutViewItem.h"
+#include "core/page/scrolling/TopDocumentRootScrollerController.h"
 #include "core/paint/PaintLayer.h"
 #include "platform/scroll/ScrollableArea.h"
 
@@ -18,13 +20,23 @@ HitTestResult hitTestResultInFrame(LocalFrame* frame,
                                    HitTestRequest::HitTestRequestType hitType) {
   HitTestResult result(HitTestRequest(hitType), point);
 
-  if (!frame || frame->contentLayoutItem().isNull())
+  if (!frame || frame->contentLayoutItem().isNull() || !frame->view())
     return result;
-  if (frame->view()) {
-    IntRect rect = frame->view()->visibleContentRect(IncludeScrollbars);
-    if (!rect.contains(roundedIntPoint(point)))
-      return result;
+
+  IntRect frameRect = frame->view()->visibleContentRect(IncludeScrollbars);
+
+  DCHECK(frame->host());
+  DCHECK(frame->document());
+  TopDocumentRootScrollerController& rootScrollerController =
+      frame->host()->globalRootScrollerController();
+  if (rootScrollerController.isRootScrollerAncestor(*frame->document())) {
+    frameRect.setSize(
+        rootScrollerController.visibleContentRect(IncludeScrollbars).size());
   }
+
+  if (!frameRect.contains(roundedIntPoint(point)))
+    return result;
+
   frame->contentLayoutItem().hitTest(result);
   return result;
 }