Tell the root layer it has a wheel handler when a select is active

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 3cd8a54068bd35a1e95930c193eb081fc28904e9..9c768d473aefd7e4cde3f72bc3357bf936739bd5 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -98,6 +98,7 @@
 #include "core/dom/KeyboardEvent.h"
 #include "core/dom/NodeRenderStyle.h"
 #include "core/dom/Text.h"
+#include "core/dom/WheelController.h"
 #include "core/dom/WheelEvent.h"
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
@@ -1531,6 +1532,8 @@ void  WebViewImpl::popupOpened(WebCore::PopupContainer* popupContainer)
     if (popupContainer->popupType() == WebCore::PopupContainer::Select) {
         ASSERT(!m_selectPopup);
         m_selectPopup = popupContainer;
+        Document* document = mainFrameImpl()->frame()->document();
+        WheelController::from(document)->didAddWheelEventHandler(document);
     }
 }
 
@@ -1539,6 +1542,8 @@ void  WebViewImpl::popupClosed(WebCore::PopupContainer* popupContainer)
     if (popupContainer->popupType() == WebCore::PopupContainer::Select) {
         ASSERT(m_selectPopup);
         m_selectPopup = 0;
+        Document* document = mainFrameImpl()->frame()->document();
+        WheelController::from(document)->didRemoveWheelEventHandler(document);
     }
 }