Remove DocumentLifecycle::Scope's setFinalState, nothing uses it.

Review URL: https://codereview.chromium.org/1290893005

git-svn-id: svn://svn.chromium.org/blink/trunk@200769 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/dom/DocumentLifecycle.h

@@ -84,8 +84,6 @@ public:
         Scope(DocumentLifecycle&, State finalState);
         ~Scope();
 
-        void setFinalState(State finalState) { m_finalState = finalState; }
-
     private:
         DocumentLifecycle& m_lifecycle;
         State m_finalState;