Consistently use only one of virtual/OVERRIDE/FINAL.

src/serialize.cc

Index: src/serialize.cc
diff --git a/src/serialize.cc b/src/serialize.cc
index 97cbd3bfce0b8d3c4b1d589c7bc8daca0687e286..e73075a46f7a339e3bcce6cd74f503b1f4f08250 100644
--- a/src/serialize.cc
+++ b/src/serialize.cc
@@ -758,7 +758,7 @@ class StringTableInsertionKey : public HashTableKey {
     DCHECK(string->IsInternalizedString());
   }
 
-  virtual bool IsMatch(Object* string) OVERRIDE {
+  bool IsMatch(Object* string) OVERRIDE {
     // We know that all entries in a hash table had their hash keys created.
     // Use that knowledge to have fast failure.
     if (hash_ != HashForObject(string)) return false;
@@ -766,9 +766,9 @@ class StringTableInsertionKey : public HashTableKey {
     return string_->SlowEquals(String::cast(string));
   }
 
-  virtual uint32_t Hash() OVERRIDE { return hash_; }
+  uint32_t Hash() OVERRIDE { return hash_; }
 
-  virtual uint32_t HashForObject(Object* key) OVERRIDE {
+  uint32_t HashForObject(Object* key) OVERRIDE {
     return String::cast(key)->Hash();
   }