Track reasons for |Node::SetNeedsStyleRecalc|

Source/core/dom/TreeScope.cpp

Index: Source/core/dom/TreeScope.cpp
diff --git a/Source/core/dom/TreeScope.cpp b/Source/core/dom/TreeScope.cpp
index 1be94a9716aa1dd9c2b0ec62f7cb338a07868b82..b078c3ee03f9675c713ed7fa64bc44f98a939fb9 100644
--- a/Source/core/dom/TreeScope.cpp
+++ b/Source/core/dom/TreeScope.cpp
@@ -542,7 +542,7 @@ void TreeScope::setNeedsStyleRecalcForViewportUnits()
             root->setNeedsStyleRecalcForViewportUnits();
         RenderStyle* style = element->renderStyle();
         if (style && style->hasViewportUnits())
-            element->setNeedsStyleRecalc(LocalStyleChange);
+            element->setNeedsStyleRecalc(StyleChangeReasonForTracing::create(StyleChangeReason::ViewportUnits), LocalStyleChange);

[esprehn, 2014/09/26 03:53:01]

Can we make this the second argument instead? Now when I'm reading the
setNeedsStyleRecalc callsites the important behavioral code is all the way at
the far end of the screen.

[kouhei (in TOK), 2014/09/29 02:05:32]

Done.

     }
 }