crypto: Tag some overridden methods with OVERRIDE.

crypto/secure_hash_default.cc

Index: crypto/secure_hash_default.cc
diff --git a/crypto/secure_hash_default.cc b/crypto/secure_hash_default.cc
index 834a276fbf9394541aa52dd37f628bdcfeb1ba39..b743b4c1c9615ec5f77bdf3a0bd0dab815c83764 100644
--- a/crypto/secure_hash_default.cc
+++ b/crypto/secure_hash_default.cc
@@ -26,17 +26,18 @@ class SecureHashSHA256NSS : public SecureHash {
   virtual ~SecureHashSHA256NSS() {
   }
 
-  virtual void Update(const void* input, size_t len) {
+  // SecureHash implementation:
+  virtual void Update(const void* input, size_t len) OVERRIDE {
     SHA256_Update(&ctx_, static_cast<const unsigned char*>(input), len);
   }
 
-  virtual void Finish(void* output, size_t len) {
+  virtual void Finish(void* output, size_t len) OVERRIDE {
     SHA256_End(&ctx_, static_cast<unsigned char*>(output), NULL,
                static_cast<unsigned int>(len));
   }
 
-  virtual bool Serialize(Pickle* pickle);
-  virtual bool Deserialize(PickleIterator* data_iterator);
+  virtual bool Serialize(Pickle* pickle) OVERRIDE;
+  virtual bool Deserialize(PickleIterator* data_iterator) OVERRIDE;
 
  private:
   SHA256Context ctx_;