Rewind the DocumentLifecycle when dirtying state

Source/core/dom/DocumentLifecycle.h

Index: Source/core/dom/DocumentLifecycle.h
diff --git a/Source/core/dom/DocumentLifecycle.h b/Source/core/dom/DocumentLifecycle.h
index 9938251e85805961df6c246b0f4e5af2664ed5ce..994ecc5f79d2a2b7384eace9ad9a265c93deab24 100644
--- a/Source/core/dom/DocumentLifecycle.h
+++ b/Source/core/dom/DocumentLifecycle.h
@@ -44,7 +44,8 @@ public:
 
         // When the document is active, it traverses these states.
 
-        StyleRecalcPending,
+        UpdatePending,

[ojan, 2014/04/09 22:43:27]

This name is a bit too general, e.g. InCompositingUpdate also does an update.
Mabye this should be called UpdateRenderTreePending to match the method name in
Document?

+
         InStyleRecalc,
         StyleClean,
 
@@ -100,11 +101,12 @@ public:
     bool stateAllowsTreeMutations() const;
 
     void advanceTo(State);
-    void rewindTo(State);
+    void ensureStateAtMost(State);
 
 private:
 #if !ASSERT_DISABLED
     bool canAdvanceTo(State) const;
+    bool canRewindTo(State) const;
 #endif
 
     State m_state;