Update V8 to r5447 as required by WebKit r67908

Change-Id: I5af6ccf18523cb7e28460e6bbc044444256cdb97
diff --git a/ChangeLog b/ChangeLog
index 95a3640..d867c6a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2010-09-13: Version 2.4.3
+
+        Made Date.parse properly handle TZ offsets (issue 857).
+
+        Performance improvements on all platforms.
+
+
 2010-09-08: Version 2.4.2
 
         Fixed GC crash bug.