Revert of Shrink initial old generation size based on new space survival rate.

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index 1bde01134c900e0ea525202c8e9375da357a9350..cb95aafc4879d620c28264693db783d2c1d87bde 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -557,7 +557,6 @@
             "Grow the new space based on the percentage of survivors instead "
             "of their absolute value.")
 DEFINE_INT(max_old_space_size, 0, "max size of the old space (in Mbytes)")
-DEFINE_INT(initial_old_space_size, 0, "initial old space size (in Mbytes)")
 DEFINE_INT(max_executable_size, 0, "max size of executable memory (in Mbytes)")
 DEFINE_BOOL(gc_global, false, "always perform global GCs")
 DEFINE_INT(gc_interval, -1, "garbage collect after <n> allocations")