Layout overflow from transforms should update frame scrollbars

Source/platform/scroll/ScrollView.cpp

Index: Source/platform/scroll/ScrollView.cpp
diff --git a/Source/platform/scroll/ScrollView.cpp b/Source/platform/scroll/ScrollView.cpp
index 420f7c6be3a383eecde856147e93835ffdb4854e..faeeb879ae7a47d4023a78b74a926e5bfcf3d56c 100644
--- a/Source/platform/scroll/ScrollView.cpp
+++ b/Source/platform/scroll/ScrollView.cpp
@@ -31,12 +31,16 @@
 #include "platform/HostWindow.h"
 #include "platform/scroll/ScrollbarTheme.h"
 #include "wtf/StdLibExtras.h"
-#include "wtf/TemporaryChange.h"
 
 using namespace std;
 
 namespace WebCore {
 
+ScrollView::InUpdateScrollbarsScope::InUpdateScrollbarsScope(ScrollView* view)

[ojan, 2014/06/11 03:04:53]

Nit: This constructor doesn't really do any work. I'd just put it in the header.

[trchen, 2014/06/11 05:04:13]

SGTM. I was hesitating.

+    : m_scope(view->m_inUpdateScrollbars, true)
+{
+}
+
 ScrollView::ScrollView()
     : m_horizontalScrollbarMode(ScrollbarAuto)
     , m_verticalScrollbarMode(ScrollbarAuto)
@@ -458,7 +462,7 @@ void ScrollView::updateScrollbars(const IntSize& desiredOffset)
 {
     if (m_inUpdateScrollbars)
         return;
-    TemporaryChange<bool> inUpdateScrollbarsChange(m_inUpdateScrollbars, true);
+    InUpdateScrollbarsScope inUpdateScrollbarsScope(this);
 
     IntSize oldVisibleSize = visibleSize();