Prepare blink to unify definitions of load completion

Source/core/dom/Document.h

Index: Source/core/dom/Document.h
diff --git a/Source/core/dom/Document.h b/Source/core/dom/Document.h
index e83c97aa18cec21599a2312bfab6a87810ad673f..f53256895acdd4efa2860dd823383c12be8445b4 100644
--- a/Source/core/dom/Document.h
+++ b/Source/core/dom/Document.h
@@ -904,6 +904,7 @@ public:
     bool processingLoadEvent() const { return m_loadEventProgress == LoadEventInProgress; }
     bool loadEventFinished() const { return m_loadEventProgress >= LoadEventCompleted; }
     bool unloadStarted() const { return m_loadEventProgress >= PageHideInProgress; }
+    void suppressLoadEvent() { m_loadEventProgress = LoadEventCompleted; }
 
     void setContainsPlugins() { m_containsPlugins = true; }
     bool containsPlugins() const { return m_containsPlugins; }