Prepare blink to unify definitions of load completion

Source/core/fetch/Resource.h

Index: Source/core/fetch/Resource.h
diff --git a/Source/core/fetch/Resource.h b/Source/core/fetch/Resource.h
index 985222bd73bf597f1ca7a29a9b2dc4adb2b58957..2a6926281bd2cf346439d90a91da0b0c2da15378 100644
--- a/Source/core/fetch/Resource.h
+++ b/Source/core/fetch/Resource.h
@@ -175,7 +175,8 @@ public:
 
     // Computes the status of an object after loading.
     // Updates the expire date on the cache entry file
-    void finish(double finishTime = 0.0);
+    void setLoadFinishTime(double finishTime) { m_loadFinishTime = finishTime; }
+    void finish();
 
     // FIXME: Remove the stringless variant once all the callsites' error messages are updated.
     bool passesAccessControlCheck(SecurityOrigin*);