Begin tracking why layout is invalidated

Source/core/layout/LayoutMenuList.cpp

Index: Source/core/layout/LayoutMenuList.cpp
diff --git a/Source/core/layout/LayoutMenuList.cpp b/Source/core/layout/LayoutMenuList.cpp
index c8a48256f91dc0b622c8264624a5aef2218bcc72..6d88791f989555f90e1420f98399b1624024ac29 100644
--- a/Source/core/layout/LayoutMenuList.cpp
+++ b/Source/core/layout/LayoutMenuList.cpp
@@ -119,7 +119,7 @@ void LayoutMenuList::adjustInnerStyle()
 
     if (m_optionStyle) {
         if ((m_optionStyle->direction() != innerStyle.direction() || m_optionStyle->unicodeBidi() != innerStyle.unicodeBidi()))
-            m_innerBlock->setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation();
+            m_innerBlock->setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(LayoutInvalidationReason::StyleChange);
         innerStyle.setTextAlign(style()->isLeftToRightDirection() ? LEFT : RIGHT);
         innerStyle.setDirection(m_optionStyle->direction());
         innerStyle.setUnicodeBidi(m_optionStyle->unicodeBidi());
@@ -197,7 +197,7 @@ void LayoutMenuList::updateOptionsWidth()
 
     m_optionsWidth = width;
     if (parent())
-        setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation();
+        setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(LayoutInvalidationReason::Unknown);

[esprehn, 2015/03/23 20:19:44]

StyleChange

[pdr., 2015/03/24 03:56:18]

This can be called for other reasons such as updateFromElement() so I went with
"MenuWidthChanged" instead of StyleChange.

I also noticed we shouldn't be setting layout here and filed
http://crbug.com/469976

 }
 
 void LayoutMenuList::updateFromElement()