Added serialization to SecureHash.

crypto/secure_hash.h

Index: crypto/secure_hash.h
diff --git a/crypto/secure_hash.h b/crypto/secure_hash.h
index 8a0f6ae66e1ea7f4edea01120ab42e70e73add1a..bff6600535850369c9a932c82be53a17b13200ce 100644
--- a/crypto/secure_hash.h
+++ b/crypto/secure_hash.h
@@ -9,6 +9,8 @@
 #include "base/basictypes.h"
 #include "crypto/crypto_export.h"
 
+class Pickle;
+
 namespace crypto {
 
 // A wrapper to calculate secure hashes incrementally, allowing to
@@ -25,6 +27,16 @@ class CRYPTO_EXPORT SecureHash {
   virtual void Update(const void* input, size_t len) = 0;
   virtual void Finish(void* output, size_t len) = 0;
 
+  // Serialize the context, so it can be restored at a later time.
+  // |pickle| will contain the serialized data.
+  // Returns whether or not |pickle| was filled.
+  virtual bool Serialize(Pickle* pickle) = 0;
+
+  // Restore the context that was saved earlier.
+  // |pickle| holds the saved data.
+  // Returns success or failure.
+  virtual bool Deserialize(Pickle* pickle) = 0;
+
  protected:
   SecureHash() {}